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COURIER HIGH SPEED MODEMS

6-8 Queries and Help Screens

LAST-DIALED NUMBER QUERY (DL?)

At this command the modem displays the number stored in the
last-dialed number buffer:

ATDL? <Enter>

STORED COMMAND STRING QUERY (&ZC?)

At this command the modem displays the command string
stored in NVRAM with the &ZC=

s command:

AT&ZC? <Enter>

HELP SCREENS

Courier modems provide five Help screens: summaries of the
basic AT command set, extended ampersand (&) command set,
Dial command options, S-Register functions, and percent (%)
command set.
NOTE: The Help screens are not available when the modem
makes a connection in synchronous mode: &M1, &M6, or &M7.

Stop/Restart Display

The following command stops the display. Hold down the
Control key and type "S":

<Ctrl>-S

To restart the display, use the same command or press any key.

Cancel Display

Either of the following commands cancels the display.

<Ctrl>-C

<Ctrl>-K

Basic Command Set ($)

At AT$, the Courier displays a screen that shows a partial
summary of the command set. A second screen, activated by
pressing any key, shows the remaining commands. The first
screen is shown in Figure 6.5.

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Summary of Contents for Courier V.34

Page 1: ...COURIER HIGH SPEED MODEM Courier V 34 Dual Standard Fax USER MANUAL ...

Page 2: ... manual s contents Chapter 1 Operating and Compatibility Features Chapter 2 Installation Chapter 3 Internal Modem Installation Chapter 4 Data Mode Commands Chapter 5 Fax Mode and Call Selection Chapter 6 Queries and Help commands to display current settings operational summaries and other data Background information on protocols error control and throughput Summaries and tables Alphabetical Comman...

Page 3: ...m s AT command set Some users prefer their communications software to take control of the modem and are more comfortable with a program that makes the modem almost transparent Others prefer a program that allows them to use the modem s AT command set sometimes and their software at other times depending on the task at hand Review at least Chapter 4 so that you have a basic understanding of the mod...

Page 4: ... V 32 terbo Fax Total Control and Adaptive Speed Leveling ASL are trademarks of U S Robotics Inc V Fast Class and V FC are trademarks of Rockwell International Any trademarks tradenames service marks or service names owned or registered by any other company and used in this manual are the property of their respective companies ...

Page 5: ...atibility Features 1 7 Chapter 2 External Modem Set Up Switches on the Modem 2 1 Front Panel Indicators on the Modem 2 2 Package Components 2 2 What You Need 2 2 An RS 232 Cable 2 2 Communications Software 2 3 Telephone Adapter 2 3 You Should 2 3 Refer to Appendix F 2 3 Refer to Appendix G 2 4 Installing the Modem 2 4 Testing the Installation 2 6 Chapter 3 Internal Modem Setup Package Components 3...

Page 6: ...s 4 11 Customizing NVRAM 4 12 Resetting the Modem 4 13 Configuration 4 13 Echo Speaker 4 13 Result Codes 4 14 Additional Result Code Sets 4 17 Modulation 4 19 Error Control Data Compression 4 19 Data Rates 4 21 RS 232 Signal Operations 4 23 Flow Control 4 24 S Registers 4 29 Inquiry and Help 4 30 Testing 4 30 International Calls Gn Pn 4 30 Miscellaneous Commands 4 31 Chapter 5 Fax Operations and C...

Page 7: ...dshaking A 2 U S Robotics V 32 terbo to U S Robotics V 32 terbo A 2 Other V Protocol Operations A 3 Dual Standard Handshaking A 4 Error Control and Throughput A 4 V 42 Handshaking A 5 MNP Handshaking A 5 Data Compression A 5 Flow Control A 6 Throughput Guidelines A 7 Typical Throughput A 8 Appendix B Summaries and Tables The RS 232 Interface B 2 Front Panel Indicators B 5 DIP Switch Summary B 7 De...

Page 8: ...e and Leased Line Operations F 15 Appendix G Additional Operations Cellular Operations G 2 Voice Data External Modems Only G 4 Hewlett Packard 3000 Installations G 8 MI MIC Operations External Modems Only G 9 Appendix H Modem Testing Testing with T H 1 Ending a Test T0 S18 H 1 Analog Loopback T1 T8 H 2 T2 H 4 Digital Loopback T3 H 4 T4 T5 H 5 Remote Digital Loopback T6 T7 H 5 Testing with Register...

Page 9: ...UR CHASER THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE AND U S ROBOTICS SHALL IN NO EVENT BE LIABLE TO PURCHASER FOR INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND OR CHARACTER Some states do not allow the exclusion or limitation of incidental or consequential damages or allow limitat...

Page 10: ...mmunications du Canada CONNECTING TO THE TELEPHONE COMPANY It is not necessary to notify the telephone company before installing the modem However the telephone company may request the telephone number s to which the Courier is connected and the FCC information printed above If the modem is malfunctioning it may affect the telephone lines In this case disconnect the modem until the source of the d...

Page 11: ... helpful How to Identify and Resolve Radio TV Interference Problems Stock No 004 000 0345 4 U S Government Printing Office Washington DC 20402 In accordance with Part 15 of the FCC rules any modification to or tampering with this device that causes harmful interference to others may be reason for prohibiting future operation FOR CANADIAN MODEM USERS The Industry Canada formerly DOC label identifie...

Page 12: ...cal ground connections of the power utility telephone lines and internal metallic water pipe system if present are connected together This precaution may be particularly important in rural areas WARNING Do not attempt to make such connections yourself contact the appropriate electric inspection authority or electrician Courier High Speed Modems Load Number 5 The Load Number LN assigned to each ter...

Page 13: ...ures and capabilities assure you of superior reliability and performance Connections up to 28 8K bps With the V 34 standard and the V Fast Class modulation scheme two modems can connect at rates up to 28 8K bps twice as fast as the rates of standard ITU T formerly CCITT V 32 bis modems which are limited to calls of 14 4K bps or less Software Upgrades Courier high speed modems are now software upgr...

Page 14: ... operating at the highest possible speed and constantly ensuring data integrity Fax Capability You can use your modem with Class 1 or Class 2 0 facsimile software to exchange faxes with millions of Group III fax machines worldwide See Chapter 5 Error Control V 42 MNP Data integrity is ensured when the modems connect with remote modems that use the V 42 LAPM HST or MNP error control protocols Error...

Page 15: ...and such as resetting the modem or executing a stored command string See Voice Data in Appendix G for instructions on use of the voice data switch Asynchronous Synchronous Capability Courier high speed modems operate synchronously as well as asynchronously A personal computer equipped with a synchronous interface adapter can call computers that use standard synchronous protocols See Appendix F for...

Page 16: ...d See Chapter 6 Modem Diagnostics ITU T V 54 loopback testing with the T command options and earlier Courier Register S16 test options are available The modem performs three loopback tests analog digital and remote digital See Appendix H for information Inactivity Timer You can set the modem to automatically hang up after a speci fied number of minutes if there is no activity on the phone line See...

Page 17: ...tom of the modem case A Dual In Line Package DIP switch guide makes it easy to tailor the switch settings to your terminal or software requirements Dialing the Last Dialed Number The modem has a buffer that stores each dialed number until it is cleared by another Dial command A few keystrokes cause the modem to redial the number in the buffer without your having to enter the number again See the D...

Page 18: ...bo 21 6K 19 2K 16 8K 14 4K 12K 9600 7200 4800 bps HST 16 8K 14 4K 12K 9600 7200 4800 bps Dual Standard modems in HST mode with ASL up to 21 6K bps HST Cellular Cellular connections at 12K 9600 7200 4800 2400 1200 300 bps Dual Standard modems in HST mode ITU T V 32 bis 14 4K 12K 9600 7200 4800 bps ITU T V 32 9600 4800 bps ITU T V 22 bis 2400 bps Bell 212A 1200 bps also V 22 ITU T V 23 1200 bps with...

Page 19: ...ronous Facsimile DCE Control Standard TIA EIA 592 Service Class 2 0 Asynchronous Facsimile DCE Control Standard ITU T V 17 14 4K 12K bps ITU T V 29 9600 7200 bps ITU T V 27 ter 4800 2400 bps ITU T V 21 300 bps Other Compatibility Features Other compatibility features include the following standards and certification Can be used with any computer or terminal that is com patible with the RS 232 stan...

Page 20: ...h V FC and V 32 bis Figure 2 1 Courier V 34 Modem Reminder To prevent overheating do not cover the vents on the top of the modem case SWITCHES ON THE MODEM Voice Data This push button switch is used primarily to switch between voice and data communications during a call Detailed instructions are in the Voice Data Calls section in Appendix G ...

Page 21: ...34 An RJ11C phone cord A power adapter Fax software and manual A Quick Reference card WHAT YOU NEED The Courier modem has minimal operational requirements Be sure to read the information in the front of this manual about radio and television interference and connecting to the phone company In addition you should be aware of the following requirements An RS 232 Cable You need an RS 232 cable to con...

Page 22: ...g configuring the modem dialing and answering calls and also enables the transfer of files and other operations Some users prefer their communications software to take control of the modem and are more comfortable with a program that makes the modem almost transparent Others prefer a program that allows them to use the modem s AT command set sometimes and their software at other times depending on...

Page 23: ...lug the adapter into a standard 115 volt AC wall socket 6 Disconnect your present phone cable from the wall jack Plug one end of the supplied phone cable into the modem s phone jack refer to the bottom label Plug the other end into the wall jack If you want to keep your telephone connected for conven tional calls plug its cord into the modem s telephone jack refer to the bottom label 7 Check the p...

Page 24: ...the DTR signal were always ON and enables the modem to accept commands Most purchased communications software however requires normal DTR 8 The final step is to connect the modem to the computer s or terminal s serial port with the RS 232 cable Attach the appropriate connectors to the modem and to the serial port POWER ON OFF PHONE JACKS SERIAL PORT INTERFACE To wall outlet To wall jack To phone T...

Page 25: ...r 7 bits plus 1 parity bit or 8 bits with no parity it doesn t matter which at this time and 1 Stop bit Set the software to use the correct serial port port through which the modem connects to the computer 3 Perform the function that lets you send AT commands to the modem that is puts the computer in Terminal mode Some communications programs do this automatically upon loading Others require you t...

Page 26: ...ications software to the correct serial port The correct serial port is the port through which the modem is connected to the computer c Make sure your software has put the computer in Terminal mode so that you can send the modem commands Then review Step 4 on the previous page d Be sure that DIP switches 1 and 6 are set ON or OFF according to your terminal or software requirements The table in App...

Page 27: ... you ll hear the dial tone from the modem s speaker To cancel the operation press any key Troubleshooting If you don t hear the dial tone first increase the volume by sliding the volume control switch towards the front of the modem If that doesn t work check to see that the phone cable from the wall jack is connected to the correct jack on the modem See Figure 2 3 If necessary reconnect the phone ...

Page 28: ...the following requirements Communications Software if the modem is attached to a computer instead of a terminal The software uses the modem s AT command set to control many communications functions including configuring the modem dialing and answering calls and also enables the transfer of files and other operations Some users prefer their communications software to take control of the modem and a...

Page 29: ...e cable attached to the PC s first serial port For this user the modem is the only device that requires a second serial port If this is your situation you can skip this entire section except for DIP Switches just before Installing the Modem Just remember that after you load your communications software you ll have to set the software to use the COM2 serial port IBM PC compatible serial ports are r...

Page 30: ...tware later The table in the next section includes hexadecimal addresses required by some software COM1 You may use this port if the computer does not have an installed serial connector at COM1 This situation is unlikely You will have to modify some switches on the modem so be sure to read this entire section of the chapter However you may prefer to leave the modem set to COM2 and proceed to DIP S...

Page 31: ...ort IRQ5 is available on 286 PCs and higher Two devices should not use the same IRQ at the same time because there will be a conflict and you will prob ably lose data For example if you use IRQ4 for a mouse installed at COM1 and for your modem installed at COM3 as shown in the previous table you cannot use the mouse and the modem at the same time Additionally if an installed device doesn t use IRQ...

Page 32: ...he contacts for the COM2 and IRQ3 settings This shunt selects the jumper by closing the circuit To change a jumper setting gently lift off the black shunt and replace it over the contacts you want As we ve said your choice of an IRQ for COM3 or COM4 depends on your hardware software configuration If the device at COM1 or COM2 isn t using IRQ4 or IRQ3 you may use one of them Otherwise check your PC...

Page 33: ...he modem is installed the DIP switches are accessible through the computer s rear panel INSTALLING THE MODEM 1 Turn off the computer and peripheral devices 2 Remove the computer s cover Refer to the computer man ual if necessary to see which rear panel screws to remove before sliding the cover off NOTE Our illustration shows expansion slots lined up ver tically on the floor of the computer Some co...

Page 34: ...ning in DIP switches 4 and a 2 inch groove These grooves are lined on both sides with metal guides Insert the modem board into the slot modem board s edge connector firmly in the 3 inch groove Figure 3 3 Inserting the Modem Screw the vertical bracket at the back of the modem firmly to the computer s rear panel as shown in Figure 3 3 This and keeps the modem board firmly in place 6 ...

Page 35: ... you to switch between voice and data transmission in the same call See Voice Data Communications in Appendix G for more information TESTING THE INSTALLATION Use the following procedures to verify that your modem is working properly 1 Turn on your computer Then turn the Courier s power switch ON The following front panel indicators or LEDs will light up on the modem CD Carrier Detect if you have s...

Page 36: ...s Don t type the angle brackets AT Enter If everything is correct the modem responds as follows OK Go on to step 5 Troubleshooting If your entered command is not displayed your local echo is OFF To turn the local echo ON send the modem the following command ATE1 Enter If double characters appear on the screen both your modem and software are set to local echo ON Either set your software to local e...

Page 37: ...switch 3 ON enabling the result codes If DIP switch 3 is OFF set it to the ON position Then initiate the new switch setting with the following reset command ATZ Enter 5 As a final check make sure the modem gets a dial tone Type the following Dial command ATD Enter On receipt of the command the modem goes off hook and waits for a dial tone The OH indicator lights up and you ll hear the dial tone fr...

Page 38: ...w these guidelines 1 Your software must be loaded and if you are using a computer it must be in Terminal mode Some communications programs put the computer in terminal mode automatically when they are loaded Others require you to display a communications terminal screen press a Function key or perform some other operation Refer to your communications software documentation for instructions In Term...

Page 39: ...he command to hang up ATH Enter is the equivalent of ATH0 Enter Example spaces are not required but are added here for readability AT K3 X2 DT 071 312 1234 Enter AT Attention a command follows K3 Disable MNP5 data compression use only V 42 bis compression X2 Use the X2 result code subset DT Dial the following number using tone dialing Enter Execute the commands This chapter groups related commands...

Page 40: ...ge of the index NOTE The defaults listed are based on the modem s shipping configuration load from nonvolatile random access memory NVRAM DIP switch 10 OFF which is the same as the F1 configuration template For a complete listing of default configuration templates see Appendix B BASIC COMMANDS AT Attention command prefix Use AT alone to test for the OK result code AT must prefix all commands excep...

Page 41: ...follows and enter Originate mode Optional parameters P Pulse dial Default T Tone dial Comma Pause for 2 seconds before continuing to dial Return to Command mode after dialing If your phone is plugged into the modem you can use this option to have the modem Auto Dial a telephone rather than a modem The Courier dials remains off hook and returns the OK message indicating it is in Command mode For ex...

Page 42: ... the next dial tone AT DT 9 W 5551234 Enter NOTE This command executes only if result code option X3 or greater has been issued If the modem is set to X2 or lower the modem interprets the W as a comma two second pause Wait for an answer with X3 or higher Some online services answer the phone and return a tape recorded request for information before processing transactions In such instances the com...

Page 43: ...e dial tone If this occurs the modem automatically reverts to pulse dialing DL Dial the last dialed number The modem stores each Dial command until it receives the next Dial command Use DL instead of A described on the next page if you wish to send the modem non Dial commands before dialing again DSn Dial the number stored in nonvolatile random access memory at position n where n 0 9 Cancel Dialin...

Page 44: ...ter NOTE The Zn s command functions differently when Dial Security is enabled See Appendix D for more information Zn Display the phone number stored in NVRAM at position n n 0 9 Redialing A Re execute the last issued command A doesn t take the AT prefix or a Carriage Return and can be used to redial A Automated Redialing A While and A can be used to continuously repeat any command they are designe...

Page 45: ...ing be sure to press any key when the result code appears during the pause before the modem begins dialing again If you press any key while the modem is dialing that dial attempt is canceled but the cycle continues Answer Mode Force Answer Mode A Force Answer mode when the modem hasn t received an incoming call Auto Answer The Courier is shipped with DIP switch 5 ON Auto Answer suppressed To set t...

Page 46: ...reverse Steps 1 or 2 above Set DIP switch 5 ON before powering on the modem or set the modem to answer on zero rings with the following command AT S0 0 Enter Points to Remember 1 If the modem is attached to a computer you can set the modem to receive calls when you re not at your computer Load your communications software as you normally do and set the modem to Auto Answer Also set your software s...

Page 47: ...r hangs up depending on the setting of DIP switch 9 DIP Switch 9 Response to OFF Modem goes on hook hangs up sends NO CARRIER result code factory setting ON Modem maintains connection Online Command mode sends OK result code The factory setting OFF forces an automatic disconnect when you issue One advantage of this is that you are not likely to inadvertently run up an all night phone bill Set DIP ...

Page 48: ...e following command once the modem sends the OK result code ATH Enter If DIP switch 9 is OFF the modem automatically hangs up on receipt of the escape code SETTING USING DEFAULTS The modem s read only memory ROM permanently stores the modem s four factory template settings Nonvolatile random access memory NVRAM allows you to save one of these four templates or add your own modifications and write ...

Page 49: ...RAM type your changes and then save them to NVRAM as in the following example The original factory template remains intact AT M2 S10 40 A2 W Enter NOTE When writing a different default configuration to NVRAM insert any additions after the Fn command but before W Otherwise they will be overwritten by Fn After sending a configuration to NVRAM you can change any setting just for the current session a...

Page 50: ...e characters appear on the screen both the modem s local echo and your software s local echo are on The Courier is shipped with DIP switch 4 OFF enabling local echo The En command controls the local echo for a current session independently of the switch setting At power on and reset the modem operates according to the DIP switch setting The En command is not stored in nonvolatile memory as a power...

Page 51: ...last digit is dialed and remains ON until carrier is established Result Codes Qn Enable suppress the display of result codes The Courier is shipped with DIP switch 3 ON to display result codes Use the Qn command to control the display for a current session independently of the switch setting At power on and reset the modem operates according to the DIP switch setting The Qn command is not stored i...

Page 52: ...AL TONE 7 BUSY 8 NO ANSWER 9 RESERVED 10 CONNECT 2400 11 RINGING 12 VOICE 13 CONNECT 9600 18 CONNECT 4800 20 CONNECT 7200 21 CONNECT 12000 25 CONNECT 14400 47 CONNECT 16800 85 CONNECT 19200 91 CONNECT 21600 99 CONNECT 24000 103 CONNECT 26400 107 CONNECT 28800 Functions Adaptive Dialing Wait for 2nd Dial Tone W Wait for Answer Fast Dial Table 4 1 Result Code Options NOTE Additional messages indicat...

Page 53: ...s used 10 CONNECT 2400 Connection with another modem at 2400 bps 11 RINGING The modem has dialed remote phone line is ringing 12 VOICE Voice answer at remote site modem hangs up 13 CONNECT 9600 Connection at reported rate Same meaning for results of 4800 18 7200 20 12K 21 14 4K 25 16 8K 43 19 2K 85 21 6K 91 24K 99 26 4K 103 or 28 8K 107 Adaptive Dialing The modem attempts to use tone dialing and i...

Page 54: ...9200 ARQ 16 CONNECT 2400 ARQ 94 CONNECT 21600 ARQ 17 CONNECT 9600 ARQ 100 CONNECT 24000 ARQ 19 CONNECT 4800 ARQ 104 CONNECT 26400 ARQ 22 CONNECT 12000 ARQ 108 CONNECT 28800 ARQ 24 CONNECT 7200 ARQ 26 CONNECT 14400 ARQ A2 Additional VFC V34 HST or V32 modulation indicator Included for users of HST Dual Standard modems If your software cannot handle the added modulation information select A1 or A0 2...

Page 55: ...CONNECT 19200 ARQ V34 A3 Additional error control indicator LAPM HST MNP SYNC or NONE and data compression type V42BIS or MNP5 Default When the call is not under one of those protocols and ARQ is not included in the result code the modem reports either SYNC indicating a syn chronous connection or NONE for no protocol If the modems are using data compression the type of compression V42BIS or MNP5 i...

Page 56: ... Both your modem and the remote modem must use the same protocol M0 Normal mode no error control Due to the nature of phone line channels this is never recommended for calls above 2400 bps M1 This setting is exclusive of the modems error control and is used only for online synchronous mode without V 25 bis See Appendix F for more information M2 Reserved M3 Reserved M4 Normal ARQ mode Default If an...

Page 57: ...ling compression K3 Selective data compression The modem negotiates only for V 42 bis compression and disables MNP Level 5 MNP5 compression Use this setting to transfer 8 bit binary files ZIP files and other files that are already compressed See the note below NOTE MNP5 compression is not useful when transferring files that are already compressed such as the ZIP files downloaded from many Bulletin...

Page 58: ...bps maximum that is V 32 Disable V 32 terbo modulation so that the modem does not switch its serial port rate up higher than 9600 bps Do this by setting Register S34 to 3 S34 3 and including that setting in the defaults you write to nonvolatile memory as shown in Setting Using Defaults earlier in this chapter Bn Serial port rate variable or fixed B0 Variable rates When the modem switches its conne...

Page 59: ...ied serial port rate When sending subsequent configurations to NVRAM be sure your software is set to your selected serial port rate so that the correct rate is maintained Nn Connection rate variable or fixed N0 Variable rates Default The Courier negotiates with the remote modem for the highest possible connection rate depending on the capabilities of the remote modem This is the recommended settin...

Page 60: ...ends a CD signal when it connects with another modem and drops the CD when it disconnects Dn Data Terminal Ready DTR operations At power on and reset the modem operates according to the setting of DIP switch 1 This command is not stored in nonvolatile memory as a power on reset default D0 DTR override The modem operates as though the DTR is always ON D1 Advance usage If issued before connecting wi...

Page 61: ...de the modem sends the DSR after it dials when it detects the remote modem s answer tone In Answer mode the modem sends the DSR after it sends an answer tone S2 This option is for specialized equipment such as automatic callback units On loss of carrier the modem sends a pulsed DSR signal with Clear to Send CTS following Carrier Detect CD S3 This is the same as S2 but without the CTS following CD ...

Page 62: ...e type you are not using The ASCII characters may be user defined See Registers S22 and S23 in Appendix B That appendix also includes an ASCII chart WARNING If possible always use hardware flow control the factory default You may lose data if XON XOFF Ctrl S Ctrl Q characters occur in the data stream from other sources They may for example come from the remote system an XON from the remote system ...

Page 63: ...ta Buffer Size Received Data refers to the data the modem receives over the phone link which the modem passes on to the attached computer The size of this buffer remains constant at 2K bytes Transmit Data Flow Control Hn This type of flow control is for data transmitted to the modem by its attached computer or terminal The modem monitors its buffer as data comes from the computer or modem If the b...

Page 64: ...es RTS This setting is required if your computer or terminal or software does not support RTS R2 Hardware flow control of received data enabled Default The modem sends data to the computer or terminal only on receipt of the RTS signal Software Control In WARNING In ordinary operation the only characters the modem recognizes during a call are the three pluses of the escape code But when software fl...

Page 65: ... not in ARQ mode there is no flow control on the phone link If you send an XOFF to your modem and it stops passing data it has no way to tell the remote computer and modem to stop sending for a while and your modem s buffer may overflow For more reliable control in non ARQ mode see I5 I3 Hewlett Packard Host mode Applies only to modems attached to an HP mainframe that uses the ENQ ACK protocol Use...

Page 66: ...ndently control the flow of data through their Transmit Data H settings Guidelines Use of software flow control may prove satisfactory if you re only transferring text files However if you re transferring non text binary files or using an Xmodem type protocol disable flow control entirely R1 I0 In addition set the modem to B0 and N0 so that the serial port and connection rates are equal S REGISTER...

Page 67: ...elephone channel Error control must be disabled for these tests See Appendix H for more information INTERNATIONAL CALLS There are three commands that apply to international calls above 1200 bps Bn Gn Pn Bn is described earlier in this chapter Gn This setting applies only to overseas calls at 2400 or 1200 bps British phone switching systems require the modem to send an 1800 Hz guard tone after it s...

Page 68: ... Call duration or Real time mode Displayed with ATI3 and ATI6 commands K0 Display current call duration if online Display last call duration if offline Default K1 Return actual time at ATI3 Clock is set using ATI3 HH MM SS K1 Yn Break handling This command allows you to send a break to abort data transfer without disconnecting from the phone link Y0 Destructive don t send Break Y1 Destructive expe...

Page 69: ...ting Register S32 to 9 with the following command ATS32 9 Enter Note that you can reset the voice data switch at any time to one of the other available functions Additionally you can overwrite the stored command string with a new one at any time Once you ve stored your command string and set Register S32 all you need to do is press the voice data switch whenever you want the command string execute...

Page 70: ...A EIA 578 Service Class 1 Asynchronous Facsimile DCE Control Standard TIA EIA 592 Service Class 2 0 Asynchronous Facsimile DCE Control Standard ITU T V 17 14 4K 12K bps ITU T V 29 9600 7200 bps ITU T V 27 ter 4800 2400 bps ITU T V 21 300 bps Fax Modem Guidelines Fax operations require facsimile compatible software that can send or receive Group III faxes Follow the instructions in your fax softwar...

Page 71: ...o indicate Data mode 1 to indicate Class 1 Fax mode or 2 0 to indicate Class 2 0 Fax mode NOTE Whenever the fax modem is reset using the ATZ command by toggling the DTR signal or by turning the power off and on the modem will be set to Data mode Fax Mode Flow Control Setting Many facsimile software products use software flow control when the modem is in Fax mode Throughout our documentation we rec...

Page 72: ... the sending machine or of such business other entity or individual Telephone facsimile machines manufactured on and after December 20 1992 must clearly mark such identifying information on each transmitted page NOTES TO PROGRAMMERS Lists of supported Class 1 fax commands and optional Class 2 0 commands are in Appendix K If you want to know more about the supported Class 1 fax commands refer to th...

Page 73: ...from multiple users Call Detection is an optional Service Class 2 0 feature and is also implemented by U S Robotics for Fax Class 1 applications To obtain a copy of the technical specification of U S Robotics implementation of Call Detection for Fax Class 1 call our BBS at 708 982 5092 and download the file CALLSEL TXT For information on implementing Fax Class 2 0 Call Detection see the standard l...

Page 74: ...performs a checksum of its read only memory ROM and returns the result to the screen This function is used only in factory testing The modem should always read the same number I2 The modem performs a test of its random access memory RAM and returns either the OK 0 or ERROR 4 result code followed by OK when the test is completed You may want to use this command as a checkpoint if the modem appears ...

Page 75: ...LAST DIALED OK Figure 6 1 Sample Result of ATI4 Command I5 The modem displays the configuration stored in nonvolatile random access memory NVRAM as in the following example If your modem connects to a modem that has Dial Security and local access enabled you cannot view the stored phone numbers ati5 USRobotics Courier Dual Standard V 34 Fax NVRAM Settings DIAL PULSE B0 F1 M1 X7 BAUD 57600 PARITY N...

Page 76: ...Link Diagnostics Screen ATI6 For calls under data compression the number of characters sent may be less than the number of octets sent due to buffering operations Line Reversals only apply to HST mode operations when the modems switch the high and low speed channels At this time online fallback is only reported Enabled in HST mode Most terms used in the display are self explanatory except for the ...

Page 77: ...s only to HST modems Fallback Enabled Disabled indicates whether or not the modems negotiated online fallback during the connection sequence Protocol Indicates the error control protocol negotiated LAPM HST MNP NONE or SYNC for a synchronous call Speed The last rates at which the receiver transmitter were operating before disconnecting Disconnect Reason Possible reasons the modem hung up are as fo...

Page 78: ...l Link Disconnect request Loop loss disconnect The modem detected a loss of current on the loop connecting it with the telephone company central office This usually occurs because the remote modem has hung up the central office drops current momentarily when there is a disconnect at the other end of a call Unless Register S38 is set higher than zero the modem immediately hangs up at loop loss Loss...

Page 79: ...sn t enabled No Prompting in Sync The originating modem did not send an autopass password and the answering modem cannot prompt for a password in any synchronous mode Non ARQ Mode The modem hung up because the originating modem was set for error control and the answering modem was set for non error control Mode Incompatible The modem hung up because both modems were not set to the same error contr...

Page 80: ... PSW N N N 5 NO PSW N N N 6 NO PSW N N N 7 NO PSW N N N 8 NO PSW N N N 9 NO PSW N N N OK Figure 6 4 Sample Dial Security Account Status Screen I11 Connection report used for debugging purposes A U S Robotics Technical Support representative may ask you for information provided on this screen S REGISTER QUERY SR This command allows you to view the contents of a particular S Register as in the follo...

Page 81: ...t Dial command options S Register functions and percent command set NOTE The Help screens are not available when the modem makes a connection in synchronous mode M1 M6 or M7 Stop Restart Display The following command stops the display Hold down the Control key and type S Ctrl S To restart the display use the same command or press any key Cancel Display Either of the following commands cancels the ...

Page 82: ...asic Commands HELP Screen Extended Command Set At AT the Courier displays a screen that shows a partial summary of the extended ampersand command set A second screen activated by pressing any key shows the remaining command set The first screen is shown in Figure 6 6 at HELP Ampersand Commands CTRL S to Stop CTRL C to Cancel An n 0 Disable ARQ Result Codes Nn n 0 Highest Link Speed n 1 Enable ARQ ...

Page 83: ... S Register Functions CTRL S to Stop CTRL C to Cancel S0 Ring to Answer On S33 Reserved S1 Counts of Rings S34 Bit Mapped S2 Escape Code Char 1 Disable V32bis S3 Carriage Return Char 2 Disable Enhanced V32 mode S4 Line Feed Char 4 Disable Quick V32 retrain S5 Backspace Char 8 Enable V23 Fallback S6 Wait Time Dial Tone sec 16 Change MR to DSR S7 Wait Time Carrier sec 32 Enable MI MIC S8 Comma Time ...

Page 84: ...8 No parity An PW ACCT E DIAL B NEW PH n 1 7 Mark parity n 0 9 n 2 7 Odd parity PW Password n 3 7 Even parity ACCT E Account Enable L PWn Security Local Access Psw DIAL B Dial Back Enable PWn 0 9 NEW New Dial Back Nn V 25bis Synchronous Clock Rate PH Dial Back Phone n 0 RESERVED Bn Remote DTE Data Rate n 1 RESERVED n 0 110 bps n 2 1200 bps n 1 300 bps n 3 2400 bps n 2 600 bps n 4 4800 bps n 3 1200...

Page 85: ...ble to errors unless the data is protected by error control The V protocol opera tions described below take place even if one of the modems is not set for error control thereby prohibiting error control for the call If your modem connects with a modem at high speed but without error control and if you are not using an error control protocol for your call you may lose data Dual Standard modems in H...

Page 86: ...nection is made using the highest compatible modulation scheme V 32 terbo V 32 bis and so on down to as low as Bell 103 or 300 bps If the remote modem has V FC capability the two modems use a line probing technique to determine the highest speed possible under current line conditions and complete the connection If the remote modem does not have V FC capability a calling Courier modem listens to th...

Page 87: ...e receiving and transmitting channels means that one channel or the other may slow down and then speed up without affecting the data flow on the other The result is more efficient line operation WARNING Answering V 32 terbo modems shift their serial port rate up to 38 4K for 21 6K connections if the calling V 32 terbo modem dials in at 21 6K The answering V 32 terbo modem then sends data to its co...

Page 88: ...ill wait until it detects a tone it recognizes the V 22 bis tone used at 2400 bps If you wish to have your Dual Standard connect with V protocol modems at high speeds make sure it is set to B0 for the ITU answer tones It will also connect with HST modems at speeds up to 16 8K bps ERROR CONTROL AND THROUGHPUT Overview Error control is available for calls at 1200 bps and above It can be disabled alt...

Page 89: ...s If the remote modem doesn t recognize an MNP Link Request error control isn t possible In HST asymmetrical mode U S Robotics modems use a proprietary scheme similar to MNP Data Compression If the modems successfully establish a V 42 connection they also negotiate for V 42 bis data compression If they successfully establish an MNP connection they negotiate for MNP5 data compression The type of co...

Page 90: ...se include ZIP files downloaded from many Bulletin Boards and 8 bit binary files which seem to the modem to be compressed MNP5 compression should not be used with such files because it adds data to them which lessens throughput The additional data is stripped when the file is decompressed by the remote modem When transferring such files it s best to set the modem to K3 this allows V 42 bis compres...

Page 91: ...are may want to enable a fixed serial port rate for ARQ calls and a variable serial port rate for non ARQ calls See the B2 command in Chapter 4 The call is under data compression The data is comprised of text files rather than binary files such as EXE or COM files See the table at the end of this appendix 2 MNP5 compression is disabled for files that are already compressed and 8 bit binary files t...

Page 92: ... with hardware flow control we recommend the most current version of Zmodem Overhead is minimal with this protocol with throughput almost equal to that obtained with no file transfer protocol Zmodem should also be used for non ARQ connections Leave the modem at its M4 and K1 settings for both error control and data compression Ymodem G is another good choice but never without both the local and re...

Page 93: ...mpression negotiated for the call and the default size 11 bit 2048 entry dictionary Straight data not already compressed no file transfer protocol Transmission from a fast 486 computer NOTE ZIP files that are already compressed or files that appear to the modem to be compressed yield lower throughput We recommend setting the modem to K3 when transferring these files to allow V 42 bis but disable M...

Page 94: ...COURIER HIGH SPEED MODEMS A 10 Link Negotiation and Error Control 28 8K bps File Type Typical throughput cps Text file 6800 ZIP files 3200 Database files 9600 Graphic files 5800 ...

Page 95: ...H SPEED MODEMS Summaries and Tables B 1 APPENDIX B SUMMARIES AND TABLES CONTENTS The RS 232 Interface with Pin Definitions Front Panel Indicators DIP Switch Summary Default Settings S Register Summary ASCII Chart ...

Page 96: ...ort at the rear of your machine which may be labeled SERIAL COMM PORT or some other term e g RS 232 If there are no labels review your machine documentation to find out which is the serial port There may be more than one Don t use a port marked PARALLEL PRINTER or AUX The physical serial port on the computer or terminal will be either a socket female or plug male that typically accom modates 25 or...

Page 97: ...cable to get the highest possible reliability performance Signal Flow DB 25 DB 9 Circuit Function Computer Modem 1 _ AA Chassis Ground both directions 2 3 BA Transmitted Data to modem 3 2 BB Received Data to computer 4 7 CA Request to Send to modem 5 8 CB Clear to Send to computer 6 6 CC Data Set Ready to computer 7 5 AB Signal Ground both directions 8 1 CF Carrier Detect to computer 12 _ SCF Spee...

Page 98: ...s You may need pin 24 which is assigned the external timing source rather than the internal modem source assigned to pin 15 See Appendix F for more detailed information Additional Flow Control Functions If your computer and software support Clear to Send and you wish to use Transmit Data hardware flow control H1 Pin 5 DB 25 or Pin 8 DB 9 is required If your computer and software support Request to...

Page 99: ... channel is reversed and your answering modem trans mits at 450 or 300 bps Also goes OFF when the modem originates a call Flashes ON for incoming ring detect CD Carrier Detect ON if DIP switch 6 is OFF factory setting and the Courier receives a valid data signal carrier from a remote modem indicating that data transmission is possible Also ON when the CD override is on DIP switch 6 ON OH Off Hook ...

Page 100: ...ter or terminal lowers RTS CS Clear to Send ON until the modem lowers CTS when Trans mit Data hardware flow control is enabled H1 H3 Always ON during synchronous connections SYN Synchronous ON when the modem is set to M1 M6 Mode M7 and enters synchronous mode Flashes when Dial Security is in operation ARQ Error Control Data Mode Automatic Repeat Request ON FAX Fax Operations when the Courier is se...

Page 101: ...when the modem is on switches 1 7 and 9 require the ATZ software reset command to initiate the new settings If you ve set switch 8 OFF to disable command recognition and want to return the modem to Smart mode so that it responds to commands just reset switch 8 to ON When you issue the ATZ command the modem reads its DIP switch settings and resets either to its defaults DIP switch 10 OFF or factory...

Page 102: ...nother modem drops CD on disconnect ON CD always ON Override 7 OFF Auxiliary DIP Switch 3 ON OFF Result codes in Originate and Answer mode ON Result codes in Answer mode disabled 8 ON AT Command Set Recognition OFF Command recognition disabled Dumb mode ON Recognition enabled Smart mode 9 OFF Escape Code Response OFF Modem hangs up returns to Command mode sends NO CARRIER result ON Modem maintains...

Page 103: ... settings are loaded instead The modem has four factory setting templates F0 F3 By default the first time the modem is turned on the modem loads the settings stored in NVRAM which are the same as the settings in factory template 1 F1 The following command example substitutes several user defined defaults for factory settings The modem also stores the rate word length and parity it detects from the...

Page 104: ...all codes except VOICE Protocol response codes A3 Full protocol codes Tone Pulse dialing P Pulse dial Online local echo F1 Disabled Speaker control M1 ON during dial through connect Remote Digital Loopback RDL T5 Deny RDL Normal Leased Cellular line L0 Normal phone line Data Set Ready operations S0 Override enabled Break handling Y1 Clear buffer send immediately Stored telephone number Z0 9 0 Blan...

Page 105: ...t rate Link rate select N0 Variable Result code subset X7 Extended Includes all codes except VOICE Protocol response codes A3 Full protocol codes Tone Pulse dialing P Pulse dial Online local echo F1 Disabled Speaker control M1 ON during dial through connect Remote Digital Loopback RDL T5 Deny RDL Normal Leased Cellular line L0 Normal phone line Data Set Ready operations S0 Override enabled Break h...

Page 106: ...otocol response codes A3 Full protocol codes Tone Pulse dialing P Pulse dial Online local echo F1 Disabled Speaker control M1 ON during dial through connect Remote Digital Loopback RDL T5 Deny RDL Normal Leased Cellular line L2 HST Cellular Carrier loss wait time S10 30 Waits 3 seconds before hanging up Data Set Ready override S0 Enabled Break handling Y1 Clear buffer send immediately Stored telep...

Page 107: ... rate select B0 Detect from AT command variable rate Link rate select N0 Variable Result code subset X1 Basic Error control response codes A1 Enabled Tone Pulse dialing P Pulse dial Online local echo F1 Disabled Speaker control M1 ON during dial through connect Remote Digital Loopback RDL T5 Deny RDL Normal Leased Cellular line L0 Normal phone line Data Set Ready operations S0 Override enabled Bre...

Page 108: ... XON character 17 S23 XOFF character 19 S24 Pulsed DSR duration 2 100th sec 150 S26 RTS CTS delay time 1 100th sec 1 S27 Bit mapped functions 0 S28 V 32 handshake time 1 10th sec 8 S29 V 21 handshake time 1 10th sec 20 S32 Voice Data Switch Options 9 S33 Bit mapped functions 0 S34 Bit mapped functions 0 S38 Disconnect wait time sec 0 S41 Allowable remote login attempts 0 S42 Remote Access ASCII ch...

Page 109: ...the modem to reset each time the computer or terminal drops its Data Terminal Ready DTR signal Turning on bit 3 of S13 causes the modem on receipt of DTR to auto dial the number stored at position 0 in NVRAM To turn on one or more bits in any bit mapped register use the total of the values shown below For example S13 9 turns on bits 0 value of 1 and 3 value of 8 Alternatively identify the bits to ...

Page 110: ...alue of 128 255 disables the escape code S3 13 Stores the ASCII decimal code for the Carriage Return character Valid range is 0 127 S4 10 Stores the ASCII decimal code for the Line Feed character Valid range is 0 127 S5 8 Stores the ASCII decimal code for the Backspace character A value of 128 255 disables the Backspace key s delete function S6 2 Sets the number of seconds the modem waits before d...

Page 111: ...odem to distinguish between a line hit or other disturbance that momentarily breaks the connection from a true disconnect hanging up by the remote modem While we do not recommend connecting the modem to a line with call waiting if you have call waiting you may wish to adjust this setting upward to prevent the modem from misinterpreting the signal for a second call as a disconnect by the remote mod...

Page 112: ...everse normal Auto Answer operation on incoming RING enter Originate Mode and look for Answer tone 2 4 Disable 250 msec pause before result code display 3 8 On DTR signal Auto Dial the number stored in NVRAM at position 0 4 16 At power on reset Auto Dial number stored in NVRAM at position 0 5 32 Disable HST used for testing V 32 terbo in Dual Standard modems 6 64 Disable MNP Level 3 used for testi...

Page 113: ...pace key to delete 6 64 Some earlier 2400 bps MNP modems not made by U S Robotics or Microcom were not fully compatible with the MNP protocol If you have difficulty making a successful 2400 bps MNP connection with a remote MNP modem it may be because of this incompati bility Set S15 to 64 and try again to make the connection 7 128 Custom applications only The default 1 5K byte non ARQ buffer allow...

Page 114: ... disabled when S18 is set to 0 See Appendix H Used to set the duration of testing in seconds before the modem automatically times out and terminates the test S19 0 Sets the duration in minutes for the Inactivity Timer The timer activates when there is no data activity on the phone line and at the timeout the modem hangs up S19 0 disables the timer S20 0 Reserved S21 10 Sets in 10 millisecond units...

Page 115: ...de S27 0 Bit mapped register To set the register see the instructions for S13 Bit ValueResult 0 1 Enable ITU T V 21 modulation at 300 bps for overseas calls In V 21 mode the modem an swers both Bell 103 and V 21 calls but only originates V 21 calls 1 2 Enable unencoded non trellis coded modulation in V 32 mode this option is part of the ITU T V 32 recommendation but is rarely used 2 4 Disable V 32...

Page 116: ...esult 0 0 Complete handshaking sequence V 42 Detection LAPM error control MNP 16 0 Disable MNP 0 32 Disable V 42 Detection and LAPM 16 32 Disable Detection phase if you know that the remote modem does LAPM but not the Detection phase S28 8 Sets the duration in tenths of a second of the extra 3000 600 Hz answer tones sent during V 32 handshaking This gives V 32 modems additional time to connect in ...

Page 117: ...32 9 Sets the function for the voice data switch This is not a bit mapped register Select the value for the desired function for example ATS32 6 ValueResult 0 Disabled 1 Voice data Originate mode See value 9 2 Voice data Answer mode 3 Redial last number 4 Dial number stored at position 0 5 Auto Answer on off toggle 6 Reset the modem 7 Initiate Remote Digital Loopback 8 Busy out phone line toggle 9...

Page 118: ...e faster retrains that occur during proprietary V 32 terbo modulation Used for troubleshooting 3 8 Enable V 23 Required for some British connections 4 16 Change MR LED to DSR 5 32 Enable MI MIC see Appendix G 6 64 Disable the remote access busy message 7 128 Disable V 32 terbo S35 S37 0 Reserved S38 0 Sets the duration in seconds before a forced hang up and clearing of the Transmit buffer when DTR...

Page 119: ...successful login attempts exceeds the limit set by this register the modem returns online and any further login attempts during the remainder of that connection are refused S42 126 Stores the ASCII decimal code for the remote access escape character The default character is a tilde S43 200 Sets the duration in fiftieths of a second of the guard time for the remote access sequence S44 15 Sets the d...

Page 120: ... 19 200 21 600 bps 3 6 _ Reserved 7 128 Custom Applications Handset Exclusion Delay If the telephone and modem share the same line and DTR is raised the modem takes control of the phone line and disconnects the voice call The modem stays on hook for the duration specified in S6 before it becomes a data call Since there is no way to detect if the telephone is in use the S6 delay occurs even if the ...

Page 121: ...1 2 1 turns on bits 0 and 2 To turn a bit off set that bit to zero as in ATS53 2 0 Bit Value Result 0 1 Dial security enabled 1 2 Prompting enabled 2 4 Local access password protection enabled NOTE In addition enabling local access password protection disables the Zn s command which stores up to ten phone numbers because stored phone numbers occupy the same space in NVRAM as the dialback numbers f...

Page 122: ...apped register used primarily by U S Robotics Technical Support for debugging purposes S56 0 Bit mapped register primarily used by U S Robotics Technical Support for debugging purposes Bit 6 ATS56 6 1 disables V 34 modulation Bit 7 ATS56 7 1 disables V FC modulation S57 0 Reserved for German operations ...

Page 123: ...ctions In Terminal mode the computer acts as if it were a stan dard terminal such as a teletypewriter rather than a data processor Keyboard entries go directly to the modem whether the entry is a modem command or data to be transmitted over the phone lines Received data is output directly to the screen 2 Type commands in either upper or lower case not a combination AT or at not At 3 All commands e...

Page 124: ... COMMAND SET Escape code operations Once the modem is online to another system the only command it recognizes is an escape code of three typed pluses which forces the modem back to Command mode Do the following when issuing the command Wait one second after sending the last item of data Type Wait one second before typing any data Do not type the AT prefix or a Carriage Return The guard time of one...

Page 125: ...T DT 1234567 Enter or AT DT 1234567 Enter The modem enters Repeat mode dials the number waits 60 seconds for a carrier default and hangs up Then after a two second pause it redials The cycle continues until the modems connect or the modem reaches a maximum of 10 attempts A Force Answer mode when the modem hasn t received an incoming call A Re execute the last issued command A doesn t take the AT p...

Page 126: ...llowed is 36 including the AT prefix punctuation and spaces The Carriage Return Enter key isn t counted as a character NOTE With the exception of the Dial options the modem ignores any commands issued after D in the same command string D Dial the number that follows and enter Originate mode Optional parameters P Pulse dial Default T Tone dial Comma Pause for 2 seconds before continuing to dial Ret...

Page 127: ...before dialing again DSn Dial the number stored in nonvolatile random access memory at position n where n 0 9 En Command mode local echo Enables disables the display of your typed commands If double characters appear on the screen both the modem s local echo and your software s local echo are on The Courier is shipped with DIP switch 4 OFF enabling local echo The En command controls the local echo...

Page 128: ...8 Reserved I9 Reserved I10 Display dial security account status information I11 Reserved Kn Modem clock operation Call duration or Real time mode Displayed with ATI3 and ATI6 commands K0 Display current call duration if online Display last call duration if offline Default K1 Return actual time at ATI3 Clock is set using ATI3 HH MM SS K1 Ln Speaker volume control internal modems only L0 Low L1 Low ...

Page 129: ...1 Return online and retrain Use to have the modem re synchronize if there were errors in a non ARQ data transfer Qn Enable suppress the display of result codes The Courier is shipped with DIP switch 3 ON to display result codes Use the Qn command to control the display for a current session independently of the switch setting Q0 Result codes displayed Q1 Result codes suppressed quiet Q2 Result cod...

Page 130: ...O DIAL TONE 7 BUSY 8 NO ANSWER 9 RESERVED 10 CONNECT 2400 11 RINGING 12 VOICE 13 CONNECT 9600 18 CONNECT 4800 20 CONNECT 7200 21 CONNECT 12000 25 CONNECT 14400 47 CONNECT 16800 85 CONNECT 19200 91 CONNECT 21600 99 CONNECT 24000 103 CONNECT 26400 107 CONNECT 28800 Functions Adaptive Dialing Wait for 2nd Dial Tone W Wait for Answer Fast Dial Z Software reset to NVRAM settings when DIP switch 10 is O...

Page 131: ...not affected by the N setting However the serial port rate must be equal to or higher than the Nn rate B2 Fixed for ARQ calls Variable for non ARQ calls Answer mode only When the modem goes off hook and connects in ARQ mode it shifts its serial port rate up to a user specified rate for example 38 4K bps If the connection is not under error control the modem behaves as if it were set to B0 and swit...

Page 132: ...f However if you change the setting of DIP switch 1 after issuing D1 the DIP switch setting tales precedence Return online with the On command or hang up with the Hn command D2 Normal DTR operations The terminal or computer must send a DTR signal for the modem to accept commands Dropping DTR terminates a call Fn The modem is shipped with four configurations templates F0 F3 stored in permanent nonp...

Page 133: ...r or terminal The modem monitors its buffer as data comes from the computer or modem If the buffer approaches 90 capacity the modem signals the computer or terminal to stop transmitting When the modem has sent enough data over the link to half empty the buffer it signals the computer or terminal to resume transmitting H0 Transmit Data flow control disabled H1 Hardware flow control Default Requires...

Page 134: ...ble disable data compression K0 Data compression disabled K1 Auto enable disable Default The modem enables compression if the serial port rate is fixed B1 and disables compression if the serial port rate follows the connection rate B0 because compression offers no throughput advantage when the serial port and connection rates are equal Compression may even degrade throughput K2 Data compression en...

Page 135: ...n M7 The modem enters V 25 bis synchronous mode using the HDLC link protocol Nn Connection rate variable or fixed N0 Variable rates Default The Courier negotiates with the remote modem for the highest possible connection rate depending on the capabilities of the remote modem This is the recommended setting and is required for the Courier V 32 terbo to connect at 21 6K bps Both modems must be U S R...

Page 136: ...untries P0 Make break ratio U S Canada 39 61 Default P1 Make break ratio United Kingdom some Commonwealth countries 33 67 Rn Received data hardware RTS flow control R0 Delay Clear to Send Response after Request to Send signal RTS CTS delay R1 The modem ignores RTS This setting is required if your computer or terminal or software does not support RTS R2 Hardware flow control of received data enable...

Page 137: ... AL testing T2 Reserved T3 Initiate Local Digital Loopback LDL testing T4 Grant Remote Digital Loopback RDL T5 Deny RDL T6 Initiate RDL testing T7 Initiate RDL with self test and error detection T8 Initiate AL with self test and error detection W Write the desired template to NVRAM using the W command W0 Write to NVRAM template 0 W1 Write to NVRAM template 1 Xn Synchronous transmit clock timing si...

Page 138: ...f data flowing in both directions Yn Break handling This command allows you to send a break to abort data transfer without disconnecting from the phone link Y0 Destructive don t send Break Y1 Destructive expedited Default Y2 Nondestructive expedited Y3 Nondestructive unexpedited modem sends Break in sequence with data received from computer or terminal ZC Display the stored command string ZC s Wri...

Page 139: ...er S32 all you need to do is press the voice data switch whenever you want the command string executed Zn s This command stores up to ten numbers where n is the position 0 9 in nonvolatile memory and s is the phone number string The number string may be up to 36 characters long including any Dial command options AT Z2 555 6789 Enter Do not include modem settings in the Zn string If the call requir...

Page 140: ...r C1 or C2 C1 Restore configuration Use this command to cancel any configuration changes made during remote access and restore the original configuration However commands that have been written to NVRAM with W will not be restored to their previous settings Additionally if you have forced immediate configuration changes with C2 those changes cannot be reversed with C1 C2 Execute configuration Use ...

Page 141: ...ommands set the computer or terminal to modem V 25 bis clock speed If the modem is set to X1 the computer is the source of the Transmit clock signals If Nn is set to 0 or 1 you will receive an error message since they are not valid values The Nn rates are as follows N0 Reserved N6 9600 bps default N1 Reserved N7 12 K bps N2 1200 bps N8 14 4K bps N3 2400 bps N9 16 8K bps N4 4800 bps N10 19 2K bps N...

Page 142: ...to certain software programs For example T could be used in a security program to identify incoming tone security codes To enable T type ATH1 Enter to force the modem off hook Then type AT T Enter To return the modem to Command mode press any key or drop the computer s or terminal s DTR signal The modem responds OK V PWn Assign the password in account n in your Courier modem s security as your aut...

Page 143: ...on at both the host and remote modem sites This appendix contains instructions for both operations WARNINGS If you want to set up Security on your Courier modem you must complete the steps below in the order listed 1 Set up your own security account Set up your local access password Enable local access password protection 2 Set up remote user accounts 3 Enable Dial Security You must set up your lo...

Page 144: ...automa tically includes an autopass password configured by the remote user to be compatible with the host modem s security in its V 42 error control request The host modem checks all the enabled passwords in its security accounts for a match If the remote user has set up the modem with an invalid password the host modem returns an INVALID PASSWORD message and hangs up If the remote user failed to ...

Page 145: ...lback offers an additional layer of security When the host modem receives a valid password that matches an account and Dialback is enabled the host first disconnects The remote user receives a NO CARRIER message Then the host modem dials back the remote modem Typically the Dialback number is stored in the Security account s phone number field However if the security account has been set up to allo...

Page 146: ... below to set up accounts where n is the account number 0 9 The fields in the above table are entered after the equal sign each separated by a comma as in the following example for account 0 with the password BILL WARNING Do not insert spaces between commas or between fields and commas Spaces will invalidate the command AT A0 BILL Y Y N 1 419 555 5555 Enter This example instructs the modem to stor...

Page 147: ...he local access password is the same as the password in account 0 AT L PW0 Enter SET UP ACCOUNTS FOR REMOTE USERS Once your account is configured and password protection has been enabled you can set up the remote user accounts Use the An command using the same guidelines you used to set up the system administrator s account in Step 1 of the previous section to set up remote user accounts Once secu...

Page 148: ...n phone numbers Stored phone numbers occupy the same space in NVRAM as the dialback numbers for Dial Security accounts and cannot be used when Dial Security is enabled If the local access password is not protected the Zn s command overwrites the corresponding Dial Security dialback number For example the following command overwrites the dialback number for account 5 AT Z5 555 8976 Enter However if...

Page 149: ...ecurity AT S your local access password Enter NOTE The modem echoes the local access password which is case sensitive The system will accept an invalid password entry but will lock you out from the modem s security commands For example if the password is Bob but you enter BOB an OK is displayed However if you try to type a security command for example ATI10 Enter to view accounts an ACCESS DENIED ...

Page 150: ...ppendix WHAT THE REMOTE CALLER NEEDS TO DO When remote users want to call in to your Courier assuming you have enabled Dial Security they must contact you to obtain a valid password They must also find out if they must set the remote modem for auto answer necessary if your modem uses Dialback as a security method 1 If the host modem security is set up get a password from the host modem operator Pa...

Page 151: ...e autopass password is set enable your Courier modem s Dial Security with the following command ATS53 0 1 W Enter 3 If Dialback is enabled at the host Courier site set your modem to answer the host modem when it disconnects and dials back To set the modem to answer the Dialback call set DIP switch 5 OFF and reset the modem ATZ Enter Alternatively type the following command AT S0 1 Enter 4 Call the...

Page 152: ...strator is unable to be at the host modem site It might be urgent for example to disable an account AT THE HOST COURIER SITE There are two tasks required to set up remote access 1 Set up password security 2 Enable remote access Set Up Password Security You can designate two passwords for remote access security each allowing a different level of access to the remote user You can assign one password...

Page 153: ...Enter or AT P1 Enter WARNING If you disable the P1 password a remote user does not need to enter a password for configuration access Enable Remote Access Set Register S41 for a value of 1 or greater S41 is used to set the number of allowable login attempts as explained later A setting of zero allows no login attempts and thus disables remote access AT S41 1 Enter NOTE This method will not work if ...

Page 154: ... NOTE You can change the escape sequence character with Register S42 The pause duration guard time can be modified with Register S43 These values are set at the host Courier modem 3 When the Courier begins its login sequence the caller will see a display similar to the following U S Robotics Courier HST Dual Standard V 34 Fax Remote Session Serial Number 000000A000000001 4 At this point if passwor...

Page 155: ...inute inactivity timer If the modem detects no activity for 3 minutes it aborts the remote access session and resumes a normal online connection Aborting the Request for Remote Access If you want to abort the remote access login before you have entered the password return online by pressing Ctrl C or typing ATO Enter Remote Viewing and Configuration Once you ve gained remote access you can communi...

Page 156: ...wever the new configu ration is immediately reflected on the information screens ATIn Remote Configuration Commands There are some additional commands that are only executable during a remote access session These commands are as follows Bn Configure the Courier s serial port rate B0 110 bps B6 9600 bps B1 300 bps B7 19 200 bps B2 600 bps B8 38 400 bps B3 1200 bps B9 57 600 bps B4 2400 bps B10 115 ...

Page 157: ... this command to force configuration changes to take effect immediately during the current connection We recommend against forcing immediate configuration changes unless absolutely necessary as this can result in an unreliable connection or even a loss of connection Fn Configure data format F0 No parity 8 data bits F1 Mark parity 7 data bits F2 Odd parity 7 data bits F3 Even parity 7 data bits Pas...

Page 158: ...erminates the connection ATO or ends the remote access session but the modems remain online CONFIGURING DIAL SECURITY REMOTELY The system administrator can configure host Courier security account information with a Courier modem at a remote site using the procedures described below NOTE Before remote configuration is possible the local modem s remote access must be enabled and a remote access pass...

Page 159: ...ation changes and execute them immediately by typing the following command AT C2 Enter 5 To end the remote session and reactivate local access security on the host modem reset the modem by typing ATZ Enter WARNING If you do not use the ATZ command to end a remote access session local access security will remain disabled at the host Courier site and anyone dialing in to your modem for remote access...

Page 160: ...iosyncracy of an off brand PC or an uncommon version of DOS may lock up the SDL program Before Establishing the Link Your modem Doesn t answer the phone or go off hook to dial a number Review your communications software manual to see what Data Terminal Ready DTR operations your software requires Then check to see if DIP switch 1 is set correctly Also check to make sure your terminal or computer i...

Page 161: ...view your communications software manual to see what Carrier Detect CD operations your software requires Then check to see if DIP switch 6 is set correctly 7 A rare condition is that your terminal or computer reverses the send receive functions at the RS 232 interface See your equipment documentation Displays double characters Both your modem s and software s local echo are on You can turn your so...

Page 162: ...e word length parity and number of Stop bits have been selected Synchronous operations review the link instructions in Appendix F If you ve set the modem to the correct configuration the problem may be with the synchronous adapter or with the system you re trying to call 3 Check to see that your modem is at the correct Bn setting to connect with either an HST modem B1 setting or V 32 terbo modem B...

Page 163: ...he problem may lie with the modem you first tried to call During Data Transfer Your screen displays Only brackets Check to make sure that both modems are set to the same bit rate word length parity and number of Stop bits If the settings are correct the problem may be with the phone line Try the following measures 1 Try placing the call again The phone company routes even local calls differently e...

Page 164: ...m hangs up when it returns to Command mode and you ll have to call again If DIP switch 9 is ON the modem maintains its connection You can return it back online by typing ATO Enter IF YOU STILL HAVE PROBLEMS The problems described above are by far the most common ones that users encounter If the suggestions we ve given don t clear up your difficulties try the following 1 Review the manual carefully...

Page 165: ...b Be sure to include your RMA number inside the package along with your name and address Put your return address and your RMA number on the shipping label as well c Ship the well packed modem to the following address Technical Support Department U S Robotics Inc 8100 North McCormick Boulevard Skokie Illinois 60076 2999 d Please note that U S Robotics will not accept packages sent COD so be sure to...

Page 166: ...nchronous responses An asynchronous device or a dumb terminal is used to configure the modem before it dials out in synchronous mode Dedicating a PC as a synchronous device by installing the proper hardware and software so it can communicate with a mainframe The modem is configured and dials out in asynchronous mode then switches to synchronous mode once a connection is made NOTE HST modulation is...

Page 167: ...n you can call The RS 232 Interface Transmit and Receive synchronous timing pins are required at the RS 232 interface You ll need either pin 15 or pin 24 for Transmitter timing signals depending on whether the modem pin 15 or the DTE pin 24 generates the signals You ll also need pin 17 for Receiver timing signals If you re building your own cable review the RS 232 Interface in Appendix B Protocol ...

Page 168: ...efault setting X0 X0 The Courier is the source of the Transmit clock timing signals and sends them to your DTE over the RS 232 interface The DTE rate will follow the connection rates Default X1 The DTE is the source of the Transmit clock timing signals and sends them to the Courier over the RS 232 interface This setting is used typically in leased line multiplexed operations Multiplexors divide th...

Page 169: ...low the instructions in Chapter 4 Command Set Usage Commands begin with a required AT prefix and end with a required Carriage Return which we denote with the symbol Enter For example the following command causes the modem to set the connection rates enable normal result codes enable auto answer select HDLC as a link protocol and save the settings to NVRAM Spaces have been added only for readabilit...

Page 170: ...speed If the modem is set to X1 the computer is the source of the Transmit clock signals If Nn is set to 0 or 1 you will receive an error message since they are not valid values The Nn rates are as follows N0 Reserved N6 9600 bps default N1 Reserved N7 12 K bps N2 1200 bps N8 14 4K bps N3 2400 bps N9 16 8K bps N4 4800 bps N10 19 2K bps N5 7200 bps Online Connection Rate The N command sets the data...

Page 171: ...result codes set the modem to X0 The normal result codes return messages such as VAL or INV VALID or INVALID whereas the extended codes offer explanations INVPS INVALID Parameter Syntax Error Automatic Answering S0 1 When the Courier is operating in V 25 bis mode it ignores the DIP switch 5 setting which controls Auto Answer To set the modem to automatically answer incoming calls set the modem to ...

Page 172: ... an incoming call CRN Call request using number provided Instructs the modem to dial the number following this command Example CRN18001234 CRS Call Request with memory location Instructs the modem to dial a number stored in memory Example CRS3 DIC Disregard incoming call Instructs the modem to disregard an incoming call overrides auto answer for this call PRNn Program number Stores a number in NVR...

Page 173: ...ication with optional parameters CFAB Abort call CFCB Local modem busy CFET Engaged tone CFFC Forbidden call CFNS Number not stored CFNT Answer tone not detected CFRT Ring tone CNX Connect LS List of numbers LSF List of forbidden numbers LSN List of stored numbers INC Incoming call INV Invalid with optional parameters INVMS Message syntax error INVCU Command Unknown INVPS Parameter syntax error IN...

Page 174: ...n it is in asynchronous mode the modem will reset when the voice data switch is pressed thus dropping DTR Returning to Asynchronous Mode Once you ve completed a communication session you can switch between synchronous and asynchronous modes by flipping DIP switch 10 OFF factory settings asynchronous mode and then ON NVRAM settings synchronous mode if the modem is set to M6 or M7 The modem cannot s...

Page 175: ...in command asynchronous mode until it makes a synchronous connection with a remote modem Upon connection the Courier enters synchronous mode and sends synchronous timing signals to your DTE Because the modem will not accept commands when it is in synchronous mode you will have to configure it in asynchronous mode before trying to connect to a synchronous network NOTE Be sure that DIP switch 1 is O...

Page 176: ...ommunications is not supported Dual Standard modems Set the Dual Standard modem to B0 Try a variable connection rate setting N0 first If that doesn t work you may have to set a fixed connection rate for example N6 9600 bps NOTE If your modem is set to a fixed rate and the remote modem is not set to the same rate your modem hangs up Connection Rate Nn Use this command to set variable or fixed rates...

Page 177: ...t pressing the voice data switch Below are our recommended procedures 1 If your communications software isn t running load the program and put the computer in Terminal mode as described in Chapter 2 Terminal mode allows you to send AT commands directly to the modem 2 Using the guidelines in Chapter 4 store a command string ZC s that configures the modem according to the Host computer s requirement...

Page 178: ... need not have your communications software loaded at the time 5 After the call restore the modem to asynchronous oper ations by powering it off and on again Answering To configure the modem for Answer mode using the voice data switch follow the instructions in the previous section Dialing Out but with these modifications Insert S0 1 in the stored command Step 2 This sets the modem to Auto Answer ...

Page 179: ...ode ENABLING REMOTE ACCESS Because synchronous equipment cannot use AT commands to configure modems a special function was designed so the modem can receive AT commands remotely To do this the modem must be placed in remote access mode with the voice data switch Press and hold down the voice data switch while powering on the modem Pressing the switch during power on causes the modem to perform its...

Page 180: ...d Telephone Line User installed lines are most commonly 2 wire lines similar to the 2 wire lines that connect residential phones to the public switched network If you are leasing a line from the telephone company request a 2 wire line the type of line the modem is designed to work with If the telephone company only makes a 4 wire line available you ll need a 4 wire to 2 wire converter at each end ...

Page 181: ...H1 enables hardware CTS flow control L1 forces the modems off hook at power on and enables them to re establish the connection should it be broken W writes the settings to nonvolatile memory NVRAM as power on defaults NOTE We recommend using the S2 setting to delay CTS until after the connection is made as a precaution If the modems are in the process of connecting or reconnecting the Courier inte...

Page 182: ...odem to Auto Answer DIP switch 5 OFF and the calling modem to Auto Answer suppressed DIP switch 5 ON 5 Power off and power on the modems This initiates the new DIP switch settings and loads the power on defaults including L1 The modems go off hook and establish the connection NOTE If the modems cannot restore the connection and you could not set the modem to S2 the reason could be a key press abor...

Page 183: ...ER HIGH SPEED MODEMS Additional Operations G 1 APPENDIX G ADDITIONAL OPERATIONS CONTENTS HST Cellular Voice Data External Modems Only Hewlett Packard 3000 Installations MI MIC Operations External Modems Only ...

Page 184: ... 200 bps and formats the data for 8 bits no parity and one stop bit The ini tialization string sent to the modem by loading this template is shown below AT B1 X7 S10 30 B1 L2 H1 I0 R2 B1 enables HST modulation X7 displays extended result codes including NO DIAL TONE RINGING NO ANSWER and BUSY messages B1 locks the serial port rate so that it remains higher than the connection rate S10 30 sets the ...

Page 185: ...are being resent shown by the ARQ LED flashing randomly some software displays the blocks retransmitted in the file transfer window you may want to reduce the packet size by doing the following 1 Be sure DIP switch 9 is ON so that the modem remains online if it receives 2 If DIP switch 9 is OFF switch it to ON and reset the modem by issuing the ATZ command 3 Send the modem the escape sequence by t...

Page 186: ...hen you install the Courier you have the option of plugging your phone into the second modular jack of the modem so it s available for voice calls You can also switch between the phone and modem during a call If the remote modem has handset exclusion you can change from voice to data and back again with or without issuing a command Handset exclusion means that if the modem is using the phone line ...

Page 187: ...an be the originate or answer modem it doesn t matter who made the phone call But one modem must first enter Originate mode and the other then enter Answer mode 2 Without hanging up the phone press the voice data switch If S32 is set to 2 Answer mode press the voice data switch immediately after the remote user forces the remote modem off hook in Originate mode 3 The other party should force the r...

Page 188: ...tion type the following command ATD Enter NOTE Be sure the modem is not set to X2 X4 X6 or X7 or it will return the NO DIAL TONE result code and hang up 3 The other party must then have the remote modem go off hook in Answer mode The following command is used to do this ATA Enter 4 If the remote modem also has handset exclusion leave both phones off hook in case you wish to switch back again to vo...

Page 189: ...nction Related Command 0 Disabled _ 1 Voice Data Originate Mode Default ATD Appendix G 2 Voice Data Answer Mode ATA Appendix G 3 Redial Last Number ATDL Chapter 4 4 Dial Number Stored at position 0 ATDS0 Chapter 4 5 Auto Answer On Off Toggle ATS0 0 or 1 Chapter 4 6 Reset Modem ATZ Chapter 4 7 Initiate Remote Digital Loopback AT T6 S16 8 Appendix H 8 Busy Out Phone Line Toggle _ 9 Execute Stored Co...

Page 190: ...s with an ACK character Courier modems manage this ENQ ACK protocol so that communication is speeded up thereby enabling HP terminals to achieve high speeds on dial up lines Special flow control settings using the I command are required for HP users These settings apply to ARQ connections only and to Courier modems set to either B0 or B1 Disregard other Courier flow control commands Set the Courie...

Page 191: ...commend you then write that setting to NVRAM as a power on default Once you ve set Register S34 have the system force the modem off hook by closing the MI MIC leads in the phone line connector The modem s OH Off Hook status light or LED goes on when the modem goes off hook SETTING THE MI MIC JUMPERS You ll have to dismantle the modem case to set the two jumper switches on the printed circuit board...

Page 192: ...apter socket Use Figure G 1 as a guide Figure G 1 Courier Modem Board 8 The jumpers are black shunts that cover two out of three upright metal contacts As shown in the figure set the jumpers so they cover the two contacts on each switch that are closest to the front panel The third contact on each switch is exposed 9 Replace the modem in the case top ease the voice data switch into the opening in ...

Page 193: ...odem case Ease the two nibs near the front corners into their openings in the front of the case top guide the rectangular slot over the volume switch and ease the back of the case bottom into place Replace the two screws the two vinyl feet and the volume slide switch cover TROUBLESHOOTING You may find that the modem does not respond to MI MIC closure which you can monitor by observing the LED Or t...

Page 194: ...n Check to see that the Off Hook OH status light goes on If you dialed a number listen for an answer tone from the remote modem Then drop the DTR signal The modem should go on hook and the OH status light should go off 5 If closure is not working properly review the steps in this section Be sure the jumper switches are in the reverse position of those in Figure G 1 If you still have problems there...

Page 195: ...ror detector In all cases disable error control before testing If the modem is detecting errors and retransmitting the affected data your results will be invalid During testing the MR status light flashes Ending a Test T0 S18 Issuing the T0 command terminates a test Alternatively set Register S18 to a specified number of seconds for example S18 10 When the 10 seconds are up the modem automatically...

Page 196: ...rd or screen It isolates the modem from the computer interface to give you a more specific result NOTE Dual Standard modems must be set to B0 default or tested at 2400 bps or lower to avoid HST asymmetrical modulation at higher speeds T1 1 If you are testing an HST or Dual Standard modem set your terminal or software to 2400 bps 2 The modem must be in Command mode If you wish set Register S18 as a...

Page 197: ...control unless you ve issued the ATZ reset command NOTE If the modem is in online command mode that is still connected to a remote modem and you send it an T1 or T8 command it drops the call enters AL mode sends a CONNECT result and waits for loopback characters T8 This AL option causes the modem to send an internal test pattern to its transmitter and loop it back to the receiver An internal error...

Page 198: ...TH or the command that resets the modem ATZ Both of the latter end the test and hang up the modem The modem hangs up and returns a three digit code followed by OK A code of 000 indicates no errors were found A code of 255 indicates 255 or more errors An ERROR message indicates that you issued an invalid command 5 If there were no errors reset the modem to M4 for error control unless you issued the...

Page 199: ...mode and the MR status light flashes 3 The remote user should type a short message It will be looped back by your modem s transmitter for verification on the remote screen You will not see the message or any other data 4 When the remote user has completed the test issue the AT T0 command to end the test Or send either ATH or the command that resets the modem ATZ The latter two commands end the tes...

Page 200: ...erify it when it is returned over the phone lines and to your screen If you select T7 the modem sends its internal test pattern and returns an error count to your screen NOTE Both test options require the modem to establish a connection and return to online command mode in response to the escape code DIP switch 9 must be set ON so that the modem does not hang up on receipt of the escape code If ne...

Page 201: ...ave not performed analog loopback testing with your modem the problem may also lie with your modem 5 Reset DIP switch 9 OFF unless you normally set that switch ON and issue ATZ to the modem to initiate the new setting Reset the modem to M4 unless you used the reset command ATZ T7 This test option causes the modem to send an internal test pattern through the Remote Digital Loopback An internal erro...

Page 202: ... The modem responds OK If you issue an invalid command the modem sends an ERROR message When you terminate the test the modem returns a three digit code followed by OK A code of 000 indicates no errors were found A code of 255 indicates 255 or more errors If you ve performed an Analog Loopback and know your modem is working properly errors indicate a problem with either the phone connection or the...

Page 203: ...les error control enters AL mode and sends a CONNECT result code The MR status light flashes 2 Type data to the modem for the modem to transmit loop to its receiver and output to the screen An alternative is to use the Test Pattern described later 3 End the test by not typing anything for one second then typing three pluses and waiting another second This forces the modem back to Command mode If D...

Page 204: ... with the T AL or RDL tests insert the test pattern command S16 4 before issuing the test command The first of the following commands initiates AL the second RDL ATS16 4 T1 ATS16 4 T6 The test pattern alone ATS16 4 is used for testing equipment and the phone line When S16 is set to 4 the modem transmits the test pattern upon connection with a remote modem Ending Testing with the Test Pattern Press...

Page 205: ...e appears send the modem the following command ATS16 8 O The modem enters RDL mode S16 8 the MR status light flashes and the modem goes back online O command Then it transmits the ITU T defined RDL signals causing the remote modem to enter RDL mode 6 Type any data at the keyboard Or send the test pattern 7 To end the test send the modem the escape code again to bring it back to Command mode 8 When...

Page 206: ...DEMS H 12 Modem Testing Keep in mind however that error control is disabled Because error control is negotiated during the connection sequence its status cannot be changed until the modem is back on hook and in Command mode ...

Page 207: ...BS ATDT 708 982 5092 Enter 2 Unless you are running an ASCII based communications program answer YES at the graphics prompt when you connect to the BBS 3 Press Enter with each prompt until you come to the main menu Download the Upgrade File 1 At the command line of the main menu type F File and press Enter Select area 5 Courier from the file area menu The most recent zipped files will display 2 Us...

Page 208: ...file checks the code embedded in itself If there is a problem an error message appears and the operation is terminated If you receive an error message download the file again 3 A screen appears with default COM port information If you want to alter the defaults use the guidelines below c n Enter this command to select one of four predefined COM ports on an IBM compatible PC Valid entries for n are...

Page 209: ... continue Type N if you want to abort the operation NOTE This is the only opportunity you will have to abort the operation 5 Once you have accepted the settings the software download will begin During this operation the Modem Ready MR LED goes out 6 When the operation has successfully completed the Modem reports download successful message displays and the MR LED lights up again Troubleshooting If...

Page 210: ...ulated into analog form looped back to the receiver demodulated into digital form and returned to the screen for verification Analog Signals Continuous varying waveforms such as the voice tones carried over phone lines Contrast with digital signals Answer Mode A state in which the modem transmits at the predefined high frequency of the communications channel and receives at the low frequency The t...

Page 211: ...ls during a call if the volume of data transfer changes Asynchronous Transmission Data transmission in which the length of time between transmitted characters may vary Because the time lapses between transmitted characters are not uniform the receiving modem must be signaled as to when the data bits of a character begin and when they end The addition of Start and Stop bits to each character serves...

Page 212: ...e channel modems are established at set bit rates commonly 300 1200 2400 4800 9600 and 14400 BPS The bits binary digits per second rate Buffer A memory area used as temporary storage during input and output operations An example is the modem s command buffer Another is the Transmit Data flow control buffer used for flow control and to store copies of transmitted frames until they are positively ac...

Page 213: ...eferred to as CCITT V 22 It is now referred to as ITU T V 22 Character A representation coded in binary digits of a letter number or other symbol Characters Per Second A data transfer rate generally estimated from the bit rate and the character length For example at 2400 bps 8 bit characters with Start and Stop bits for a total of ten bits per character will be transmitted at a rate of approximate...

Page 214: ...on When the transmitting modem detects redundant units of data it recodes them into shorter units of fewer bits The receiving modem then decompresses the redundant data units before passing them to the receiving computer Data Compression Table A table of values assigned for each character during a call under data compression Default values in the table are continually altered and built during each...

Page 215: ...ace and the cable that connects the terminal or computer and the modem The modem receives data in the form of digital signals from the computer or terminal and immediately returns the data to the screen for verification Digital Signals Discrete uniform signals In this manual the term refers to the binary digits 0 and 1 Duplex Indicates a communications channel capable of carrying signals in both d...

Page 216: ...ow Control A mechanism that compensates for differences in the flow of data input to and output from a modem or other device Frame A data communications term for a block of data with header and trailer information attached The added information usu ally includes a frame number block size data error check codes and Start End indicators Full Duplex Signal flow in both directions at the same time In ...

Page 217: ...cient use of the phone channel at speeds of 4800 bps and above HST also incorporates MNP compatible error control procedures adapted to asymmetrical modulation Hz Hertz a frequency measurement unit used internationally to indicate one cycle per second ITU T International Telecommunication Union Telecommunication sector Formerly referred to as CCITT An international organization that defines standa...

Page 218: ...e no Auto Dial capability yet must go off hook in Originate mode to connect with answering modems See MI MIC Closure in Appendix G MNP Microcom Networking Protocol an asynchronous error control protocol developed by Microcom Inc and now in the public domain The protocol ensures error free transmission through error detection CRC and retransmission of errored frames U S Robotics modems use MNP Leve...

Page 219: ...at the high frequency The transmit receive frequencies are the reverse of the called modem which is in Answer mode Parallel Transmission The transfer of data characters using parallel electrical paths for each bit of the character for example 8 paths for 8 bit characters Data is stored in computers in parallel form but may be converted to serial form for certain operations See Serial Transmission ...

Page 220: ...configuration screens and change the Courier s configuration Password protection is available Remote Digital Loopback A test that checks the phone link and a remote modem s trans mitter and receiver Data entered from the keyboard is trans mitted from the initiating modem received by the remote modem s receiver looped through its transmitter and returned to the local screen for verification Remote ...

Page 221: ... only support synchronous communications unless their owners have installed a synchronous adapter and appropriate software Terminal A device whose keyboard and display are used for sending and receiving data over a communications link Differs from a microcomputer in that it has no internal processing capabilities Used to enter data into or retrieve processed data from a system or network Terminal ...

Page 222: ...mpatible fax devices then transmit or receive at higher speeds V 21 Modem An ITU T standard for modem communications at 300 bps Modems made in the U S or Canada follow the Bell 103 stan dard However the modem can be set to answer V 21 calls from overseas V 22 A ITU T standard for modem communications at 1200 bps compatible with the Bell 212A standard observed in the U S and Canada V 22 bis An ITU ...

Page 223: ...for facsimile operations that specifies modulation at 9600 bps with fallback to 7200 bps V 32 An ITU T standard for modem communications at 9600 bps and 4800 bps V 32 modems fall back to 4800 bps when line quality is impaired and fall forward again to 9600 bps when line quality improves V 32 bis An ITU T standard that extends the V 32 connection range 4800 7200 9600 12K and 14 4K bps V 32 bis mode...

Page 224: ...sion V Fast Class V FC Proprietary modulation scheme developed by Rockwell International for data communication speeds up to 28 8K bps Word Length The number of bits in a data character without parity start or stop bits Xmodem The first of a family of error control software protocols used to transfer files between modems These protocols are in the public domain and are available from many bulletin...

Page 225: ... 19 2K 16 8K 14 4K 12K 9600 7200 bps synchronous Trellis Coded Modulation TCM 4800 bps synchronous asynchronous Quadrature Amplitude Modulation QAM U S Robotics High Speed Technology HST 16 8K 14 4K 12K 9600 7200 bps synchronous asynchronous asymmetrical 450 bps back channel with automatic handshake adjustment to 300 bps Trellis Coded Modulation TCM Quadrature Amplitude Modulation QAM 4800 bps syn...

Page 226: ...s Differential Phase Shift Keying DPSK Bell 103 300 bps asynchronous Frequency Shift Keying FSK ITU T V 21 300 bps asynchronous Frequency Shift Keying FSK Error Control Standards ITU T V 42 error control protocol at 14 4K 12K 9600 7200 4800 bps V 32 bis mode and at 2400 1200 bps U S Robotics HST error control protocol asymmetrical mode at 16 8K 14 4K 12K 9600 7200 4800 bps 450 300 bps back channel...

Page 227: ...U T V 21 300 bps SERIAL PORT RATES 115 2K 57 6K 38 4K 19 2K 9600 4800 2400 1200 300 bps ADAPTIVE SPEED LEVELING 21 6K 19 2K 16 8K 14 4K 12K 9600 7200 4800 bps PHONE LINE INTERFACE RJ11 RJ45S phone jacks COMMUNICATIONS CHANNEL Full half duplex on 2 wire dial up dedicated or leased phone lines demand driven high speed channel turnaround in HST mode symmetrical speeds in V 32 bis mode OPERATIONAL MOD...

Page 228: ... bps AA Auto Answer Answer CD Carrier Detect OH Off Hook RD Received Data SD Send Data TR Terminal Ready DTR MR Modem Ready Test mode RS Request to Send CS Clear to Send SYN Synchronous mode ARQ Error control connection established FAX Modem in Fax mode FLOW CONTROL BUFFERS Transmit Buffer Error control 3 25k bytes Non Error control 1 5k bytes 128 byte option Receive Buffer 2K bytes COMMAND BUFFER...

Page 229: ...mable 2 255 sec ANSWER TONE TIMEOUT 60 sec FAX SERVICE CLASS 1 COMMANDS FCLASS n 0 1 Class identification and control FTS n 0 255 Stop transmission and pause 10ms FRS n 0 255 Wait for silence 10 ms FTM n 3 24 48 72 73 74 96 121 122 145 146 Transmit data with carrier FRM n 3 24 48 72 73 74 96 121 122 145 146 Receive data with carrier FTH n 3 24 48 72 73 74 96 121 122 145 146 Transmit HDLC data with...

Page 230: ...p Status Code read only FMS 0 3 Minimum Phase C Speed FBS 500 100 Buffer size read only V 25 BIS SYNCHRONOUS COMMANDS AND RESULT CODES Commands Connect incoming call CIC Call request using number provided CRN Call Request with memory location CRS Disregard incoming call DIC Program number PRNn Request list of forbidden numbers RFN Request list of stored numbers RLN Dial options 0 9 P T Result Code...

Page 231: ...2200 2300 Hz LOSS OF CARRIER DISCONNECT TIMER 0 7 sec default programmable 0 2 25 5 sec EQUALIZATION Adaptive TRANSMITTER CARRIER FREQUENCIES V 34 Originate Mode 1800 Hz Answer Mode 1800 Hz Originate Mode 1829 Hz Answer Mode 1829 Hz Originate Mode 1867 Hz Answer Mode 1867 Hz Originate Mode 1920 Hz Answer Mode 1920 Hz Originate Mode 1959 Hz Answer Mode 1959 Hz Originate Mode 2000 Hz Answer Mode 200...

Page 232: ...er Mode 1800 Hz USR HST 450 bps back channel Originate Mode 375 Hz Answer Mode 1800 Hz USR HST 300 bps back channel Originate Mode 350 Hz Answer Mode 1800 Hz V 23 Originate Mode Mark 390 Hz Space 450 Hz Answer Mode Mark 1300 Hz Space 2100 Hz V 22 bis V 22 Bell 212A Originate Mode 1200 Hz Answer Mode 2400 Hz Bell 103 Originate Mode Mark 1270 Hz Space 1070 Hz Answer Mode Mark 2225 Hz Space 2025 Hz ...

Page 233: ...de 1800 Hz Answer Mode 1800 Hz Originate Mode 1829 Hz Answer Mode 1829 Hz Originate Mode 1867 Hz Answer Mode 1867 Hz Originate Mode 1920 Hz Answer Mode 1920 Hz Originate Mode 1959 Hz Answer Mode 1959 Hz Originate Mode 2000 Hz Answer Mode 2000 Hz V Fast Class Originate Mode 1800 Hz Answer Mode 1800 Hz Originate Mode 1875 Hz Answer Mode 1875 Hz Originate Mode 1920 Hz Answer Mode 1920 Hz ...

Page 234: ...e 1800 Hz USR HST 450 bps back channel Originate Mode 1800 Hz Answer Mode 375 Hz USR HST 300 bps back channel Originate Mode 1800 Hz Answer Mode 350 Hz V 23 Originate Mode Mark 1300 Hz Space 2100 Hz Answer Mode Mark 390 Hz Space 450 Hz V 22 bis V 22 Bell 212A Originate Mode 2400 Hz Answer Mode 1200 Hz Bell 103 Originate Mode Mark 2225 Hz Space 2025 Hz Answer Mode Mark 1270 Hz Space 1070 Hz ...

Page 235: ... Hz Space 1850 Hz Answer Mode Mark 980 Hz Space 1180 Hz RECEIVE SENSITIVITY 44 dBm 2 dBm TRANSMIT LEVEL 9 dBm maximum TRANSMITTER FREQUENCY TOLERANCE 01 CERTIFICATION FCC Part 68 and Part 15 Class B Domestic IC Canada UL listed POWER CONSUMPTION 5 watts SIZE 6 375 x 10 3 x 1 337 inches ...

Page 236: ...D 14 D 15 E erase Dial Security parameter s C 18 C 19 D 8 F configure data format C 19 D 15 L local security password C 19 D 5 N synchronous DTE rate C 19 F 4 F 5 Pn s password security C 19 D 10 D 11 D 15 Pn display password C 19 D 15 S Dial Security status C 19 D 7 T Tone recognition 4 32 C 20 V autopass password C 20 D 9 A force answer mode 4 8 C 3 A repeat last command 4 7 C 3 A continuous rep...

Page 237: ...ng Assembly External modem Chapter 2 Internal modem Chapter 3 Asterisk dialing 4 4 C 4 AT command 4 1 C 1 C 3 Audio monitor speaker 4 14 Auto answering disabling 4 8 4 9 number of rings on which to answer S0 4 9 B 14 reverse S13 B 18 see Voice Data switch options suppress S0 B 14 with Dip switch 5 4 8 Autobaud 4 21 Auto dialing Help screen D 6 10 S13 B 18 see Stored phone numbers see Voice Data sw...

Page 238: ...rence Card Bottom panel of an external modem Command set recognition see DIP switch 8 Communications software see Software Compatibility 1 6 1 7 error control 4 20 4 21 fax 5 1 Components 2 2 3 1 COM port 3 3 3 4 see Serial port Compressed files 4 20 A 5 A 6 Compression see Data compression Computer interface serial port speed select B 4 21 4 22 Configuration general assembly Chapters 2 and 3 comm...

Page 239: ...al echo DIP 4 result code display quiet mode DIP 3 Result codes verbal numeric DIP 2 Disable Call Indicate S54 B 27 Detection Phase S27 B 22 HST S13 B 18 MNP S27 B 22 MNP V 42 S51 B 26 MNP3 S13 B 18 MNP4 S15 B 19 Online Fallback S15 B 19 Retrains S14 B 18 V 32 S27 B 21 V 32 bis S34 B 24 V 32 terbo S34 B 24 V 34 S56 B 28 V 42 Detection and LAPM S27 B 22 V 8 S54 B 27 V FC S56 B 28 Voice Data Switch ...

Page 240: ...ate settings B 13 Ground xii Group III 1 2 1 6 5 1 GSTN Clear Down 6 5 Guard time Escape code S12 B 14 remote S43 B 14 tone G 4 31 Guidelines command usage 4 1 4 2 C 1 C 2 H Half duplex 4 14 Handset exclusion G 4 delay S51 B 26 Handshake Dual Standard A 4 MNP A 5 options Bn 4 18 C 4 V 34 A 1 A 2 V 42 A 5 V FC A 2 V Protocol A 3 A 4 V terbo A 2 Hanging up H 4 9 4 10 synchronous F 9 HDLC F 1 F 2 Har...

Page 241: ...cked rate see Fixed variable Login attempts allowed remote S41 B 14 Loopback tests Appendix H Loop loss 6 15 Low performance template settings B 13 M Maintenance Security Appendix D Canada xii U S E 5 E 6 Make break ratio P 4 31 C 14 Messages see Result Codes MI MIC closure G 9 enable S34 B 24 operations G 9 G 11 troubleshooting G 11 G 12 MNP Microcom Networking Protocol error control 4 19 data co...

Page 242: ...2 6 1 Rate select commands serial port rate B 4 21 4 22 connection rate N 4 22 4 23 synchronous timing rate N F 4 F 5 RD see LEDs RDL see Remote Digital Loopback Read only memory 4 11 Real time mode K 4 31 Received data flow control I R 4 27 4 28 Redial re execute continuous A 4 8 one time A 4 7 see Voice Data switch options Reduce packet size S33 G 3 Re execute A 4 7 C 3 Remote access Appendix D ...

Page 243: ...ial operation see Cancel dialing Store command string ZC s inquiry ZC 4 32 6 8 using for synchronous mode F 12 Stored command string ZC 1 3 4 32 C 16 C 17 see Voice Data switch options Store phone number Zn s 4 7 C 17 inquiry 4 7 Switches see DIP switches and Voice Data Symbol rate S54 B 27 SYN see LEDs Synchronous adapter card F 10 enable protocols M C 12 C 13 F 6 operations Appendix F RS 232 req...

Page 244: ...see V Protocol handshake time S28 B 21 V 32 bis 1 6 disable S34 B 24 handshaking A 3 V 32 terbo 1 6 disable S34 B 24 handshaking A 3 V 34 1 6 connection rates 1 1 connection report I11 6 7 defined J 15 disable S56 B 28 handshaking A 1 A 2 V 42 1 6 detection phase A 5 handshaking A 5 V 42 bis 1 6 A 5 A 6 V 54 1 6 Appendix H V 8 defined J 15 disable S54 B 27 V Fast Class V FC 1 6 connection rates 1 ...

Page 245: ...COURIER HIGH SPEED MODEMS 10 Index X Xmodem type protocols 4 25 4 29 XID 6 6 XON XOFF 4 25 4 28 character assignments S22 and S23 B 14 B 20 Y Ymodem A 8 Ymodem G A 8 Z ZIP file A 6 Zmodem A 8 ...

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