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Fax Operation

 V.3400

9-7

Receive Silence   +FRS=

(Time)

The command +FRS= causes the modem to listen for silence and report 
back an OK result code when the line has been silent for the specified 
amount of time.  The (Time) value is in 10 ms increments from 0 to 2.55 
seconds.

The modem aborts the command and sends an OK result code if the 
DTE sends an additional character, which is discarded, during the 
command execution.  This command returns an ERROR result code if 
issued while the modem is on hook.

Fax Transmit and Receive Modes

The following commands instruct the modem to transmit or receive 
facsimile data with the designated modulation.  Flow control, data buff-
ering, and data filtering are used as appropriate, in accordance with the 
Class 1 specification.  Each of these commands must be the last 
command on the command line.     

The modem accepts one of the values listed in Table 9-1.    

Command

 Description

 

+FTM=(MOD)

Transmit data with (MOD) carrier

+FRM=(MOD)

Receive data with (MOD) carrier

+FTH=(MOD)

Transmit HDLC data with (MOD) carrier

+FRH=(MOD)

Receive HDLC data with (MOD) carrier

Table 9-1. Modulation Values 

Value

 Modulation

 

Speed

 

3

V.21 channel 2

300 bps

24

V.27 ter

2400 bps

48

V.27 ter

4800 bps

72

V.29

7200 bps

73

V.17

7200 bps

74

V.17

7200 bps *

96

V.29

9600 bps

97

V.17

9600 bps

Содержание V.3400

Страница 1: ...r Class 1 fax mode The LCD display indicates when fax mode is enabled The V 3400 default configuration is for data mode Service Class is normally only changed by the software as necessary Previous chapters in this manual contain information about the modem that should be understood prior to fax operation Those chapters should be read before this chapter Users should understand the fax software man...

Страница 2: ...ault command when the fax software is first loaded Subse quent fax operations may not reset the fax profile and if a fax required option has been changed by the user fax operation will not work An example of a fax initialization command is AT F V E S0 0 This can be interpreted as AT F Reset the active profile to the factory default V Set response messages to digit code E Disable local echo off S0 ...

Страница 3: ... changes between fax transmissions and if required reset the fax profile for the next fax transmission CLASS 1 DETAILS Operation as a fax modem complies with EIA 578 details of Class 1 operation and compatibility are found in that standard There is no need to be familiar with these details since they are handled by the Class 1 software package but this section briefly summarizes some of them As a ...

Страница 4: ...normally issued by the fax software and not by the user They are provided here for reference While only the lower order 7 bits of each character are used for commands and parameters Phase C data transmission or reception requires all 8 data bits Therefore a data format which uses 8 data bits should be used for fax mode Dial Command D The dial command D described in Chapter 5 tells the modem to go ...

Страница 5: ...before the A command is issued use the FCLASS 1 command If the modem is in the online command state when an answer command is issued e g a connection is already established modem returns an ERROR result code Otherwise it answers the call and generates a 2100 Hz CED answer back tone in accordance with T 30 The modem then enters V 21 Channel 2 transmit state with HDLC framing and returns a CONNECT r...

Страница 6: ...can be determined with the FCLASS command A 0 response indicates the modem is configured for data mode while a 1 indicates it is set for fax mode This informa tion text is preceded and followed by CR LF in addition to being followed by an appropriate result code response Service Class Capabilities FCLASS The available Service Classes can be revealed by the FCLASS command The modem responds with th...

Страница 7: ...wing commands instruct the modem to transmit or receive facsimile data with the designated modulation Flow control data buff ering and data filtering are used as appropriate in accordance with the Class 1 specification Each of these commands must be the last command on the command line The modem accepts one of the values listed in Table 9 1 Command Description FTM MOD Transmit data with MOD carrie...

Страница 8: ...d selected with the Mod parameter If the selected carrier is detected a CONNECT result code is sent to the DTE if a different signal is detected the modem sends a FCERROR CONNECT ERROR result code and returns to command mode This command is aborted if the DTE sends any character to the modem other than DC1 or DC3 during this mode For additional information consult the Class 1 specification HDLC Tr...

Страница 9: ...any of the fax transmit or receive commands can be determined with the FTx or FRx command where x is M H or S The normal transmit and receive capabilities are interrogated with FTM and FRM while the HDLC transmit and receive capabilities are interrogated with FTH and FRH Since the modem can send and receive normal data or HDLC data at all valid speeds up to 14400 bps the modem returns the informat...

Страница 10: ... for transferring files between computers with fax modems using a Binary File Transfer BFT standard Although the received file is not a fax image transmit ting the file is similar to sending a fax Since the modem allows T 30 error correction mode with HDLC framing up to 9600 bps fax mode can also be used for BFT if supported by the Class 1 software package The Binary File Transfer is an option in ...

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