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brain boxes

4.22 Edition April 2001

PARALLEL, SERIAL AND IEEE INTERFACE

P.S.I. BOX

Summary of Contents for P.S.I. BOX

Page 1: ...brain boxes 4 22 Edition April 2001 PARALLEL SERIAL AND IEEE INTERFACE P S I BOX...

Page 2: ...e circuitry or manual may be duplicated copied transmitted or reproduced in any way without the prior written consent of BRAIN BOXES PSI BOX is designed manufactured and supported by BRAIN BOXES Unit...

Page 3: ...huge range of industry standard IEEE 488 devices The PSI BOX PLUS includes a disk with two sample communications programs for use in Mode 7 Your interface is designed and manufactured in England and...

Page 4: ...PLUS includes an extra mode as standard Mode 7 This mode allows any computer with an RS232 port to act as the controller of a whole bus full of IEEE instruments Mode 7 has a powerful but easy to under...

Page 5: ...llel Port gives details of the parallel port connector pin outs the function of Centronics Output DIP switch and the Centronics LEDs the parallel port input and output handshake Chapter 5 The RS232 Se...

Page 6: ...llocation Mode 7 is typically used as a means of controlling a whole bus full of IEEE instruments from the RS232 serial port of any computer Chapter 8 The IEEE BUS Command Language Controls and Functi...

Page 7: ...to work with as wide a range of computers IEEE devices and peripheral as possible Of course we have not tried EVERY IEEE device and EVERY computer available but we ve yet to find one that can not be...

Page 8: ...EEE 488 Interface Bus Standard Chapter 3 The IEEE Port Chapter 4 The Centronics Parallel Port Chapter 5 The RS232 Serial Port Chapter 6 The PSI BOX Modes 1 6 8 With Typical Application Examples Chapte...

Page 9: ...ower LED 6 Chapter 2 An Introduction to IEEE 488 Bus Standard Introduction 9 The IEEE 488 Standard 9 The Beginnings Of A New Standard 9 What Exactly Is IEEE 488 10 What s In A Name 10 IEEE 488 1975 11...

Page 10: ...vice Trigger 22 Remote Local Functions 23 End Of Sequence Termination 23 Chapter 3 The IEEE Port Introduction 25 The IEEE Leds 26 The IEEE DIP Switches 27 Setting The IEEE Address 28 Setting The Contr...

Page 11: ...andshake 39 The Hard Wired Handshake 40 The XON XOFF Handshake 41 Setting The Parity Options 43 Setting The Data Word Length 43 RS232 Port Cables 44 Connecting To An IBM PC Serial Port 44 Connecting T...

Page 12: ...0 Figure 6 2 HPGL Output Commands 65 Figure 6 3 HPGL RS232 I f Flow Control Commands 66 Chapter 7 The PSI BOX Mode 7 Overview Introduction 68 Mode 7 In 15 Minutes 68 Mode 7 Summary 69 Mode 7 Power Up...

Page 13: ...ar Command 95 DISABLE Prevents Devices Responding Parallel Poll 96 END Set The End Of Output Method 97 END OFF Disable EOI During A Bus Write 99 END ON Set The End Of Output Method 100 EOI Send A Data...

Page 14: ...eset Character 139 SEC Sends The Secondary Address 140 SDC Sends Selective Device Clear Command 141 SHOW Display Explain Control Status String 142 SPD Sends Serial Poll Disable Command 143 SPE Sends S...

Page 15: ...es allow the user to select options whilst the LEDs are used to monitor progress of data transfers The set of DIP switches nearest the LEDs is switch block one The switches dedicated to the RS232 port...

Page 16: ...The RS232 handshake can be either a hardware handshake controlled by the DSR CTS DCD and DTR RTS pins or by the XON XOFF software handshake The baud rate and parity options are selectable from either...

Page 17: ...n be used to convert between RS232 and Centronics parallel The following modes of operation are currently available In modes 1 and 2 the PSI BOX is an IEEE 488 device attached to an IEEE controller co...

Page 18: ...ntrol language is used to address many IEEE devices and to provide complete instrumentation control MODE 7 RS232 bi directional to IEEE 488 full control of _______ _ IEEE bus of up to 14 instruments o...

Page 19: ...has a 2 byte buffer This two byte buffer gives a better flow of data than actually having no buffer at all Figure 1 2 Buffer Option ______________________ _ DIP 8 BUFFER OPTION CHOSEN _____ __________...

Page 20: ...e connections and the mains switches If you still have trouble please contact your dealer Figure 1 4 The Power LED ________________________ _ Talk Listen Xmit Recvr Centr O P Centr I P Power On Once y...

Page 21: ...elect the IEEE base address This gives the address of the RS232 port the address of the Centronics Parallel port is one more than the base address set by the dip switches 5 If the IEEE port is acting...

Page 22: ...y problems BUT if you do it probably due to the RS232 port cross over cable being wired incorrectly First make sure that you have read the followed the steps above next re read the relevant sections o...

Page 23: ...s of the IEEE 488 system are described If you know little about IEEE we suggest that you browse though the first two parts of this chapter and then carefully read the rest The IEEE 488 Standard ______...

Page 24: ...n unambiguous way the IEEE 488 standard has become powerful though its ease of use and straight forward implementation Any one who has ever attempted to link two RS232C devices together will admire th...

Page 25: ...ted together is digital Bit Parallel means that 8 lines are used to simultaneously transmit a whole byte of data These 8 lines are called collectively the Data Bus The data on the bus ranges in value...

Page 26: ...arry data and commands Three lines control the transfer of the data Whilst the remaining five lines are for general interface management These three groups are the 8 Data Bus signals the 3 Handshake s...

Page 27: ...is driven by all the devices that are accepting data from the data bus The NRFD line is false when the all these devices are ready for data and true when one or more of them is not ready for data NDA...

Page 28: ...controller to place the bus interface in a known inactive state Only the System Controller can set the IFC line all other instruments must monitor and respond to IFC The System Controller may set IFC...

Page 29: ...EEE bus users is that the IEEE signals are described as using negative logic This simply means that a signal is true when it is low at 0 4 Volts or less and that a signal is false when it is high at 2...

Page 30: ...he IEEE Bus __________________ _ Types Of IEEE Devices ____________________ _ Every device on the IEEE bus must be capable of acting in at least one of following three roles 1 A device acting as a LIS...

Page 31: ...e are several controllers present on the IEEE bus only one of them at a time can be the Controller In Charge When a controller is not the Controller In Charge it must be in the controller idle state T...

Page 32: ...ies The System Controller alone can set the IFC and REN signals true or false The System Controller can make itself the Controller In Charge at any time by sending the IFC signal true for 100 micro se...

Page 33: ...ices 2 Addressed commands accepted by all devices addressed to listen 3 Addresses accepted by ALL devices 4 Secondary addresses or commands accepted by all devices enabled by a primary address or comm...

Page 34: ...nterface messages that allow the controller to accomplish the following four functions 1 Serial Polls 2 Parallel Polls 3 Device Clear and Device Trigger 4 Remote Local functions Serial Poll _________...

Page 35: ...vices have the ability to assert service request and respond to serial polls Parallel Poll ___________ The Parallel Poll function allows the IEEE controller to periodically check selected bus devices...

Page 36: ...tial state depends on the particular devices function Device clearing is very useful when a device hangs or inadvertently is placed in unresponsive mode It is worth noting that not all IEEE devices ar...

Page 37: ...local control unless it has been put into the LOCAL LOCKOUT state Whenever a read or write is performed or whenever any bus command is sent the PSI BOX reasserts the REN line The GTL Go To Local and...

Page 38: ...d all listeners must know what byte ALWAYS marks the end of a string The talker should only send its EOS byte as the last byte in the data stream The listeners on detecting this EOS byte recognise tha...

Page 39: ...Amphenol IEEE 488 connector with screw locks for secure connections is used The IEEE plug is gold plated and EMI shielded The IEEE port lines are implemented with the PSI BOX in one of two modes 1 The...

Page 40: ...is one higher than this base address and is the IEEE to Centronics Parallel converter address Each port may be addressed using secondary addresses These secondary addresses allow the IEEE controller t...

Page 41: ...BOX internal buffer The IEEE DIP Switches _____________________ DIP switches 1 5 on switch block 1 in conjunction with the MODE switch 7 8 are used to set the all the IEEE options These options includ...

Page 42: ...RT 1 On 0 0 0 1 RS232 PORT 2 CENTRONICS PORT 0 1 0 0 2 RS232 PORT 3 CENTRONICS PORT 1 1 0 0 3 RS232 PORT 4 CENTRONICS PORT 0 0 1 0 4 RS232 PORT 5 CENTRONICS PORT 1 0 1 0 5 RS232 PORT 6 CENTRONICS PORT...

Page 43: ...ler State ____________________________ 5 IEEE Controller on off 12345678 DIP 5 CONTROLLER STATE CHOSEN _____ ________________________ 0 Off PSI BOX IS AN IEEE DEVICE 1 On PSI BOX IS THE IEEE CONTROLLE...

Page 44: ...___ _ PIN SIGNAL PIN SIGNAL ___ ______ ___ ______ 1 DATA 1 13 DATA 5 2 DATA 2 14 DATA 6 3 DATA 3 15 DATA 7 4 DATA 4 16 DATA 8 5 EOI 17 REN 6 DAV 18 GROUND 6 7 NRFD 19 GROUND 7 8 NDAC 20 GROUND 8 9 IFC...

Page 45: ...ort it provides TTL logic level signals The connector has the same pin out as the IBM PC parallel port LPT1 etc A 25 way female D connector with screw locks for secure connections is used The port may...

Page 46: ...rom its buffer to the parallel bus LED 4 CENTR I P flashes whenever the Centronics Parallel port of the PSI BOX receives a byte from the printer port of a computer the byte is stored in the PSI BOX in...

Page 47: ...he Centronics Output Handshake ______________________________ _ The Centronics port output handshake is as follows A If the Centronics printer is busy it should raise the BUSY line true The PSI BOX wi...

Page 48: ...PSI BOX is busy or if its Centronics input buffer is full it will raise the BUSY line true Any data that is sent to the PSI BOX while the BUSY line is high is LOST Even though the Centr i p LED may fl...

Page 49: ...with male to male 25 pin D connectors as shown in figure 4 4 is all that is required Since in the PSI BOX the PE line pin12 is pulled low and ERROR line pin 15 and the SELECT line pin 13 are pulled hi...

Page 50: ...5 DATA 3 INPUT TO PSI BOX 6 DATA 4 INPUT TO PSI BOX 7 DATA 5 INPUT TO PSI BOX 8 DATA 6 INPUT TO PSI BOX 9 DATA 7 INPUT TO PSI BOX 10 ACKNOWLEDGE OUTPUT FROM PSI BOX 11 BUSY OUTPUT FROM PSI BOX 12 PE O...

Page 51: ...rt The connector has the same pin outs as the IBM PC serial port COM1 etc A 25 way male D connector with screw locks for secure connections is used The serial port is bi directional The baud rate and...

Page 52: ...s buffer to the serial bus LED 4 RCVR flashes whenever the RS232 port of the PSI BOX receives a byte from the serial bus the byte is stored in the PSI BOX internal buffer Figure 5 1 The RS232 Leds ___...

Page 53: ...ting The Baud Rate ____________________ DIP switches 1 3 on switch block 2 are used to set the RS232 baud rate The range of baud rates is 75 19200 baud Figure 5 3 Baud Rate Settings __________________...

Page 54: ...ss or tears using only 3 wires TxD RxD and ground Figure 5 4 Selecting The RS232 Handshake ______________________________________ _ 4 Xon Xoff on off 12345678 DIP 4 RS232 HANDSHAKE CHOSEN _____ ______...

Page 55: ...__ _ The XON XOFF handshake works in the following manner The output lines DTR and RTS are sent out low and the PSI BOX does not care what state the CTS DSR and DCD inputs are It is recommended that i...

Page 56: ...yte is received it will send an XOFF code to the other device If it continues to receive data it will send further XOFF codes to the device the data received will be lost since there is no room in the...

Page 57: ...y the PSI BOX is determined by the parity and data word length chosen No Parity 2 STOP bits are always sent Parity Enabled 7 data bits gives 2 STOP bits 8 data bits gives 1 STOP bit Setting The Data W...

Page 58: ...s over cable is simply to ensure that the right signals going out of one RS232 port go into the appropriate lines of the other RS232 port Connecting To An IBM PC Serial Port __________________________...

Page 59: ...nnecting a MODEM to the PSI BOX then you will not need a cross over cable and a straight through cable connecting pins 1 8 and 20 is all that is required Figure 5 7 The RS232 Port Pin Outs ___________...

Page 60: ..._____ 2 TxD TRANSMITTED DATA OUTPUT FROM PSI BOX 3 RXD RECEIVED DATA INPUT TO PSI BOX 4 RTS REQUEST TO SEND OUTPUT FROM PSI BOX 5 CTS CLEAR TO SEND INPUT TO PSI BOX 6 DSR DATA SET READY INPUT TO PSI B...

Page 61: ...______ PSI BOX SERIAL PORT Side IBM PC SERIAL PORT Side ________________________ ________________________ USE 25 Pin Female D Connector 9 Pin Female D Connector _____________________________ _________...

Page 62: ...______ SIGNAL PIN PIN SIGNAL ______ ___ ___ ______ GROUND 5 1 GROUND 7 GROUND DCD 1 8 DCD RXD 2 3 RXD TXD 3 2 TXD DTR 4 20 DTR DSR 6 6 DSR RTS 7 4 RTS CTS 8 5 CTS RI 9 22 Ring Indicator This cable mak...

Page 63: ...re mode switches which have a dedicated role DIP switches 7 8 on switch block 1 have no dedicated function but are used in conjunction with the DIPs 5 6 to define the mode of operation of the PSI BOX...

Page 64: ...L IEEE TO CENTRONICS OUTPUT 2P 0 1 0 1 MODE 2 With Pet To PC Ascii Conversion 3 1 0 0 0 CENTRONICS INPUT TO RS232 OUTPUT 4 1 1 0 0 RS232 INPUT TO CENTRONICS OUTPUT 5 1 0 1 0 CENTRONICS INPUT TO IEEE O...

Page 65: ...t port of the PSI BOX The PSI BOX acts like two separate IEEE devices one device is an IEEE to RS232 interface the other device is an IEEE from parallel interface Listen Only Operation _______________...

Page 66: ...in its buffer to send then a talk with nothing to say message is sent this is the 00 byte with EOI true This method of flagging an empty buffer prevents a hang up in the handshake In a similar manner...

Page 67: ...generally used to connect standard RS232 Ascii printers to CBM Pet or C64 128 computers Unlike all other PSI BOX modes in Mode 1 the state of DIP switch 8 IS monitored whilst the PSI BOX is in operat...

Page 68: ...PSI BOX acts like two separate IEEE devices one device is an IEEE to RS232 interface the other device is an IEEE to parallel interface Listen Only Operation ____________________ The PSI BOX can also...

Page 69: ...only This prevents a hang up in the handshake In Mode 2 half the PSI BOX ram acts as the Centronics output buffer the other half is evenly split between the RS232 input and output buffers Pet To PC A...

Page 70: ...rom IEEE controller computer Unlisten from IEEE controller computer In modes 1 and 2 the Data from the IEEE port to the controlling computer is PSI BOX talk address from IEEE controller computer Data...

Page 71: ...n input to PSI Box DCD is bit 4 decimal value 16 an input to PSI Box 15 PSI Box sends an identification message memory size and software revision date eg P S I BOX V4 3 02 05 90 32K S A Listen Functio...

Page 72: ...printer or plotter This is a popular way of connecting the HP Laser Jet printer via a buffer to the parallel port of a PC Data is received according to the Centronics input handshake and output accord...

Page 73: ...llel printer or plotter This is often used as a method of placing parallel printers etc in a remote location with the data being sent down a twisted pair RS232 line at high speed Data is received acco...

Page 74: ...other sort of data transmission is possible Talk Only Operation __________________ _ The PSI BOX can also be set to act as a Talk Only IEEE from Centronics parallel input interface To select the List...

Page 75: ...can be accessed when in this mode The address of the IEEE device that the PSI BOX accesses is as set on the IEEE address DIP switches The PSI BOX sends a LISTEN command to the IEEE bus before each dat...

Page 76: ...ion is possible Use Mode 8 for IEEE plotter control from a computer s RS232 serial port Talk Only Operation __________________ _ The PSI BOX can also be set to act as a Talk Only IEEE from RS232 input...

Page 77: ...be accessed when in this mode The address of the IEEE device that the PSI BOX accesses is as set on the IEEE address DIP switches The PSI BOX sends a LISTEN command to the IEEE bus before each data by...

Page 78: ...ommands 1 Execution Of HPGL Plotting Commands __ ___________________________________ _ Most HPGL commands are concerned with positioning and selecting pens plotting shapes and specifying line thicknes...

Page 79: ...ng and output commands that the two plotters understand are identical the RS232 plotter also responds to several FLOW CONTROL commands that are absent from IEEE plotters These Flow Control commands re...

Page 80: ...e 8 requires the plotter to both listen to HPGL plotting commands and reply to HPGL output command the plotter must be set for addressed operation It must not be set for Listen only use The PSI BOX ac...

Page 81: ...for further responses If the PSI BOX receives a Flow Control command then it immediately responds to it in the appropriate way If the RS232 input buffer of the PSI BOX becomes full then it will signa...

Page 82: ...EEE devices IEEE control status string the RESET command and character the current device a summary of the BUS command language and finally the Mode 7 memory allocation Mode 7 In 15 Minutes __________...

Page 83: ...o edit the source code and either recompile or run the program using the BASIC interpreter PSIBOX EXE ____________ _ The PSIBOX BAS file is the source code for the compiled PSIBOX EXE program The PSIB...

Page 84: ...rect to the current IEEE device the data is thus passed straight through from the RS232 port to the IEEE bus Mode 7 Power Up ________________ The basis of the Mode 7 IEEE handler is an intelligent com...

Page 85: ...omputer This message consists of the current PSI BOX rom version and the default IEEE control status string PSI BOX Version 4 0f 16 03 90 STATUS 04 0 1 1 0 00 00000 00000 000 000 000 0 0 1 etc The my...

Page 86: ...ata to passed straight though the PSI BOX to the current IEEE device At the start of the data stream the PSI BOX sends the current device LISTEN address Then the current secondary address if any Then...

Page 87: ...cii string containing IEEE bus keywords and numeric parameters These keywords are interpreted as commands to perform Serial or Parallel Polls send any IEEE bus commands or specify the timeout period T...

Page 88: ...a carriage return All the parameters in an BUS command are numerals 0 9 or are any mix of upper or lower case letters a z and A Z with the characters Parameters are separated by spaces or commas Extr...

Page 89: ...Whilst these methods the main differences lie in the fact that the addressing of the devices has to be explicitly given when using the DATA and STRING commands but that the OUTPUT command addresses th...

Page 90: ...what manner it should control the bus This table of data is called the IEEE control status string The IEEE control status string also holds information on parallel and serial poll responses time out d...

Page 91: ...string will be sent from the PSI BOX to the RS232 host computer whenever the PSI BOX receives the STATUS command BUS STATUS Carriage Return Alternatively for increased ease of use a BUS command withou...

Page 92: ...S on i p bit3 no device present 16 2 000000 65535 The number of bytes read from bus on last input 22 26 00000 65535 The number of bytes sent to the bus on last output 28 30 000 255 The SERIAL POLL dat...

Page 93: ...mand and character Whenever the PSI BOX receives the reset character from the RS232 host computer it performs a power on reset Everything is returned to the default state and an IEEE bus ABORT command...

Page 94: ...evice 6 with a secondary address of 2 as the current device send the following sequence CR BUS 6 2 Carriage Return The first two fields of IEEE control status string will be updated to reflect the inf...

Page 95: ...dress PPC Parallel Poll Configure PPD Parallel Poll Disable PPE Parallel Poll Enable PPU Parall Poll Unconfigure SDC Select Device Clear SPE Serial Poll Enable SPD Serial Poll Disable TAD Talk Address...

Page 96: ...MOTE Asserts REN line continuously true sets ATN false SHOW Display Explain Control Status String SPOLL Serial Polls the current device SPOLL 6 7 Serial Polls devices 6 and 7 STATUS Sends the current...

Page 97: ...l then it will be unable to receive more RS232 data until the IEEE device accepts data from the PSI BOX If the RS232 output buffer of the PSI BOX becomes full then the PSI BOX will be unable to receiv...

Page 98: ..._____ _ With the Mode 7 language covering such a wide range of functions a variety of parameters is required for the different IEEE command keywords Some IEEE commands require no parameters some comma...

Page 99: ...EE device 2 with sa of 4 add list A list of none one or more primary addresses with optional secondary addresses Here are several examples of valid address lists The action that is taken eg Serial Pol...

Page 100: ...Decimal number in the range 00000 65535 Used to specify how many bytes of data to be read using the ENTER command sppp Parallel Poll data The range is 00 15 and is used to specify how and on which dat...

Page 101: ...nuing All bus devices return to their device dependent power on state and become ready to receive address or other IEEE commands from the PSI BOX Byte 9 in the IEEE control status string contains 1 wh...

Page 102: ...Byte 9 in the IEEE control status string contains 1 when the ATN line is asserted true controller active and 0 when the ATN line is false controller active At the end of each data transfer sequence A...

Page 103: ...command DCL or a series of listen addresses followed by the SDC command is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The CLEAR comman...

Page 104: ...dary commands correct The PSI BOX asserts ATN if not already true and becomes the active controller Use NO ATN to drop ATN false again when you have finished sending your stream of commands The bit 7...

Page 105: ...IG 24or 152 SPE SERIAL POLL ENABLE 25or 153 SPD SERIAL POLL DISABLE 32or 160 LAG 0 LISTEN ADDRESS 0 62or 190 LAG 30 LISTEN ADDRESS 30 63or 191 UNL UNLISTEN 64or 192 TAD 0 TALK ADDRESS 0 94or 222 TAD 3...

Page 106: ...specified device performs the PPC PPE sequence as explained in the PPE command explanation As well as the device address the CONFIGURE command requires a number in the range 0 15 This parameter has t...

Page 107: ...line 5 true during PPOLL device 3 is asserts data line 6 true during PPOLL if they require service Bus Activity ___________ _ assert ATN if not already so UNT UNL LAG of specified device PPC PPE incl...

Page 108: ...s being sent The PSI BOX drops ATN false if not already so at the end of the data sequence ATN is left false until further instructions makes the PSI BOX become the active controller Use ATN to set AT...

Page 109: ...er then the IEEE command DCL hex 14h decimal 20 is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The DCL command is used automatically in...

Page 110: ...ng to the parallel poll All the devices will need to be reCONFIGUREd if they are to take part in future parallel polls If one or more device addresses are given then those devices are commanded to Lis...

Page 111: ...its Alternatively using EOS ON the EOI signal can be set when the last byte in the current string is output this is the default condition Format _______ a END EOI never sent true during an IEEE bus wr...

Page 112: ...bus in several chunks so preventing the IEEE device from thinking that the output has finished early BUS END 13 8 The EOI line is set true only when the PSI BOX sends the Carriage Return character 13...

Page 113: ...and so prevents the listener terminating the bus handshake early Alternatively using EOS ON and EOS the EOI signal can be set when the last byte in the current string is output or EOI can be set true...

Page 114: ...is output Alternatively the PSI BOX can be instructed never to set EOI true or EOI can be set true when a particular character in the range 00 255 is the last byte to be sent from the PSI BOX The PSI...

Page 115: ...N false if not already so at the end of the EOI with data sequence ATN is left false until further instructions makes the PSI BOX become the active controller Use ATN to set ATN true again when you ha...

Page 116: ...regardless of the value of the EOS terminator byte if a talker sets EOI true with a byte sent to the PSI BOX then the PSI BOX knows that the sequence has ended Format _______ a EOS Bus inputs termina...

Page 117: ...only terminate when the device sets the EOI true when sending its last data byte BUS EOS 13 8 All inputs from the IEEE bus device terminate when the device sends the Carriage Return character 13 BUS E...

Page 118: ...ontroller then the IEEE command GET hex 08h decimal 8 is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The GET command is used automatica...

Page 119: ...d becomes the active controller then the IEEE command GTL hex 01h decimal 1 is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The GTL comm...

Page 120: ...tivity to stop immediately Good to use IFC or ABORT shortly after power on as the first IEEE bus command so that the IEEE bus devices are put into a known state The IFC command is usually issued when...

Page 121: ...ey should listen to the addressed commands or data that follows the listen command The LAG command can also be sent by using CMD 32 62 or CMD 160 190 or by using LISTEN 0 30 or 128 158 Format LAG 1 Te...

Page 122: ...ey should listen to the addressed commands or data that follows the listen command The LISTEN command can also be sent by using CMD 32 62 or CMD 160 190 or by using LAG 0 30 or 128 158 Format LISTEN 1...

Page 123: ...vices buttons interfering with its operation The device will return to local control when it receives the GTL command or when the IEEE REN line goes false The PSI BOX asserts ATN and becomes the activ...

Page 124: ...are now under front panel control If one or more devices addresses are given then those devices are commanded to Listen and then told via the GTL command to respond to their front panel controls rath...

Page 125: ...This is necessary when you want the instrument to be totally under the control of the PSI BOX It prevents accidental pushing of the devices buttons interfering with its operation The device will retu...

Page 126: ...can be used in an automated fashion whilst the controlling terminal is busy performing other jobs The MACRO command followed by only spaces and a carriage return will cause the PSI BOX to send the cu...

Page 127: ..._ Returns DEPENDS ON USERS COMMAND SPECIFIED IN _________ _ MACRO Example ________ _ BUS MACRO REM lists the current macro BUS MACRO OUTPUT SET ENTER REM current macro is now the sequence OUTPUT SET E...

Page 128: ...ON Messages are usually switched off when a fully debugged program is used to acquire large amounts of data via the PSI BOX without having to process the extra data associated with the PSI BOX messag...

Page 129: ...ON Messages are usually switched off when a fully debugged program is used to acquire large amounts of data via the PSI BOX without having to process the extra data associated with the PSI BOX message...

Page 130: ...number of listeners can be listening simultaneously to one talker The PSI BOX asserts ATN and becomes the active controller then the listen address of the PSI BOX is sent over the IEEE bus After the...

Page 131: ...f the PSI BOX from the default value of 0 to an other address more convenient to the user Bytes 50 51 in the IEEE control status string contains the current MLA of the PSI BOX Format MLA _________ Par...

Page 132: ...ll have to supply your own special features for the PSI BOX secondary addresses The MSA should only be sent immediately after a MTA or MLA command PSI BOX asserts ATN and becomes the active controller...

Page 133: ...he default value of none to an other address more convenient to the user Bytes 53 54 in the IEEE control status string contains the current MSA of the PSI BOX Format MSA _________ Params One address i...

Page 134: ...talker can be active on the bus at a time this command automatically UNTalks any other talkers The PSI BOX asserts ATN and becomes the active controller then the Talk address of the PSI BOX is sent o...

Page 135: ...f the PSI BOX from the default value of 0 to an other address more convenient to the user Bytes 56 57 in the IEEE control status string contains the current MTA of the PSI BOX Format MTA _________ Par...

Page 136: ...ains 1 when the ATN line is asserted true controller active and 0 when the ATN line is false controller idle The PSI BOX will return to the idle state in between each data transfer sequence Format NO...

Page 137: ...en the REN line is asserted true PSI BOX remotely controlling bus devices and 0 when the REN line is false IEEE devices under local control Whenever a read or write is performed or whenever any bus co...

Page 138: ...BOX must wait for it to print the current buffer contents and so make room for more input During this wait time the PSI BOX will timeout the IEEE printer or plotter To prevent this timeout occuring an...

Page 139: ...a factor of 2 The timeouts can also be disabled using NOTO or by TO 0 Format NO TO _________ Params None _________ Returns The IEEE control string holds the current timeout _________ _ value in posit...

Page 140: ...the sequence The EOI line is set true concurrent with the last data byte according to how the END parameter is set The default is sent only with CR character The OUTPUT command is a simple method of s...

Page 141: ...addressed listener which particular data line it is to use when responding to a parallel poll the PPE command also tells the addressed device whether to assert the line when it requires service or to...

Page 142: ...erence Control Functions Bus Activity ___________ _ assert ATN if not already so PPC recommended sequence if not using CONFIGURE UNT UNL LAG PPC PPE includes line assignment and sense bit data UNL Pag...

Page 143: ...s sequence to be performed The PPD command is used to tell the addressed listener that it must no longer respond to the controller s parallel poll command Though unable to respond the device remembers...

Page 144: ...PSI BOX PLUS Reference Control Functions UNT UNL LAG PPC PPD UNL Page 130 Chapter 8...

Page 145: ...nding to a parallel poll the PPE command also tells the addressed device whether to assert the line when it requires service or to assert the line when it does not require service The PPE command has...

Page 146: ...PPE command can also be sent by using CMD 96 111 or CMD 224 239 or SEC 0 15 Format PPE _________ Params One in the range 0 15 _________ Returns None _________ _ Example ________ _ BUS PPE 1 recommende...

Page 147: ...one command The PSI BOX knows which device is responsible for which data line because it has previously assigned those lines to each device using the PPC with PPE commands Depending on the Parallel Po...

Page 148: ...36 38 hold the _________ _ parallel poll response Example ________ _ BUS POLL REM ISSUE COMMAND BUS STATUS REM READ STRING PP at position 36 REM PP 000 to 255 Bus Activity ___________ _ assert ATN and...

Page 149: ...nt the ATN remains true PSI BOX is the active controller The PPU command is used to make all devices that have the Parallel poll ability unable to respond to a parallel poll command For a device to re...

Page 150: ...and again to retrieve a whole string of data however this is a tedious method a much easier solution is the ENTER command The PSI BOX drops ATN false if not already so at the start of the data input...

Page 151: ...e ready to receive instruction from the PSI BOX controller Byte 11 in the IEEE control status string contains 1 when the REN line is asserted true PSI BOX remotely controlling bus devices and 0 when t...

Page 152: ...ol status string contains 1 when the REN line is asserted true PSI BOX remotely controlling bus devices and 0 when the REN line is false IEEE devices under local control Whenever a read or write is pe...

Page 153: ...rned to the default state and an IEEE bus ABORT command is performed An ABORT command pulses the IFC line for approximately 100 micro seconds then asserts the REN and ATN line true This reset function...

Page 154: ...Red with hex 060h 96 decimal and is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The SEC should only be used after a listen address or a...

Page 155: ...the active controller then the IEEE command SDC hex 04h decimal 4 is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The SDC command is use...

Page 156: ...eparated by commas It is a table of information about the IEEE bus the PSI BOX and the current device Now that the status string is over 100 bytes long the SHOW command has been added to enable the us...

Page 157: ...n be called separately to finish your own serial poll routine The SPD command can also be sent by using CMD 25 or CMD 153 Format SPD _________ Params None _________ Returns Only if used as part of a f...

Page 158: ...devices that can request service instead of serial polling them sequentially using SPOLL you may wish to poll them together You would then use SPE as part of your own routine The SPE command can also...

Page 159: ...Control Functions PSI BOX PLUS Reference drop ATN and read serial poll status byte SPD UNT Chapter 8 Page 145...

Page 160: ...g by the controller Format SPOLL serially polls the currently addressed device _________ The serial poll response is stored in bytes 28 30 the current device serial poll data and in bytes 32 34 the fi...

Page 161: ...D WE TRY THE RIGHT DEVICE REM MUST BE ANOTHER DEVICE REQUESTING SERVICE REM GOT RIGHT DEVICE IF SP REM SP HOLDS REASON FOR SRQ Bus Activity SPOLL or SPOLL n ______________ UNL MLA SPE TAD drop ATN ACP...

Page 162: ...ddress The current PSI BOX status string will be sent from the PSI BOX to the RS232 host computer whenever the PSI BOX receives the STATUS command Alternatively for increased ease of use a BUS command...

Page 163: ...lete compatibility with future version of the Mode 7 software The format of the data returned is given in chapter 7 Format STATUS _________ Params None _________ Returns Up to 255 bytes of data starti...

Page 164: ...simply sends the text enclosed in the delimiters to the bus The STRING command is a simple method of adding text in the middle of a bus data exchange Format OUTPUT HELLO _________ Params Delimiter str...

Page 165: ...addressed at one time else confusion would reign The TAD command is treated as an UNTALK command by all the other talkers When the current talker recognises that another talker has been addressed to t...

Page 166: ...addressed at one time else confusion would reign The TALK command is treated as an UNTALK command by all the other talkers When the current talker recognises that another talker has been addressed to...

Page 167: ...SI BOX is the active controller The NO ATN command should be used to drop the ATN line false so allowing the addressed controller to assert ATN and become the active controller The TCT command is used...

Page 168: ...l The interval range is from 1 to 65535 milli seconds ie from 1 1000th of a second to 65 535 seconds It must be noted that due to the overhead of decoding the command etc timings less than 100 milli s...

Page 169: ...be ready to handshake data The TO parameter is used to determine the length of wait before the PSI BOX times the device out Bytes 57 and 58 in the IEEE control status string contains the current time...

Page 170: ...second wait till timeout TO 10 1 Second 1000 milli seconds TO 11 2 Second wait till timeout TO 12 5 Second wait till timeout TO 13 10 Second wait till timeout TO 14 20 Second wait till timeout TO 15...

Page 171: ...asures the current in milli Amps the TRIGGER 2 3 command performs the test on the resistor If no device address is specified then the PSI BOX simply sends the GET command this will active all currentl...

Page 172: ...t performs identically to the PPU command it prevents all devices which have been previously CONFIGUREd from responding to parallel polls All the devices will need to be reCONFIGUREd if they are to ta...

Page 173: ...mes the active controller then the IEEE command UNL hex 03Fh decimal 63 is sent over the IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The UNL command...

Page 174: ...he IEEE bus After the command has been sent the ATN remains true PSI BOX is the active controller The UNT command is used automatically in the read routine when data is read to the bus using the ENTER...

Page 175: ...sent from the PSI BOX to the RS232 host computer whenever the PSI BOX receives the VERSION command A request for the VERSION causes the PSI BOX to return a message to the RS232 host computer This is a...

Page 176: ...al The interval range is from 1 to 65535 milli seconds ie from 1 1000th of a second to 65 535 seconds It must be noted that due to the overhead of decoding the command etc timings less than 100 milli...

Page 177: ...he timeout using the NO TO command Once the SRQ line has been asserted true you should perform a serial poll using the SPOLL command to determine which device has requested service and exactly why On...

Page 178: ...command cannot call itself IE The X command cannot be embedded within a macro command string otherwise an error is flagged when the macro is executed Used carefully and intelligently the X and MACRO c...

Page 179: ...9 81 82 87 88 89 90 93 94 95 96 101 104 105 107 108 109 110 111 116 118 120 122 126 127 128 129 131 132 133 134 135 136 137 139 140 141 143 144 145 147 150 151 152 153 157 158 159 160 Attention 14 20...

Page 180: ...37 59 69 Commodore 7 28 49 51 52 54 55 60 62 69 Commodore pet 7 28 49 51 52 54 55 Compiled 69 Configure 1 6 21 22 81 82 86 92 93 127 128 129 132 133 135 Connecting 10 44 45 47 58 Controller 3 4 7 14 2...

Page 181: ...143 145 147 153 Dsr 2 40 41 45 46 47 48 57 Dtr 2 40 41 44 45 46 47 48 57 End 6 15 23 24 56 67 71 72 77 79 82 85 87 88 94 97 99 100 101 102 112 126 End marker 79 End 82 97 98 99 End off 97 98 99 End on...

Page 182: ...M PC 2 31 35 37 44 46 47 48 51 58 70 IBM PS 2 69 Idle 17 20 122 135 Ieee bus status 78 Ieee cables 29 Ieee commands 61 63 66 68 70 74 84 87 88 90 137 159 Ieee control data 78 Ieee controls 79 Ieee dev...

Page 183: ...66 Llo 81 82 91 109 111 Local 14 20 23 81 82 90 91 105 109 110 111 123 137 138 Local lockout 23 81 91 109 111 137 138 Lockout 23 81 82 91 109 111 137 138 LOTUS 60 62 64 LOTUS 123 60 62 64 Lpt1 2 31 3...

Page 184: ...arallel poll enable 81 131 Parallel poll response 22 133 134 Parallel poll status 22 71 133 Parallel poll unconfigure 135 Parallel port 2 7 26 31 32 33 35 51 58 69 Parallel port direction 33 Parallel...

Page 185: ...138 143 144 145 147 156 160 Read data 77 134 Reading data 24 Receiving data 56 68 75 Remote 14 23 59 72 77 80 82 87 123 137 138 Ren 13 14 17 18 23 25 30 70 72 78 79 81 82 87 109 110 111 123 137 138 1...

Page 186: ...145 Serial port 2 37 44 46 47 48 59 62 69 Service request 14 20 21 146 Software handshake 2 40 Source code 69 Spd 81 91 143 144 145 147 Spe 81 91 143 144 147 Speed 9 10 16 59 77 Spoll 74 78 81 82 84 8...

Page 187: ...125 155 156 163 Timer 82 154 162 Trigger 20 22 81 82 104 157 Unconfigure 81 82 135 158 Unl 19 72 74 75 81 89 91 93 94 96 101 110 126 127 128 129 130 132 147 150 153 157 159 164 Unlisten 56 81 86 90 91...

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