Multi-Tech Systems MT3334SMI manual Class 2 Fax Command Implementation, +Faa, +Faxerr

ModemModule Developer’s Guide

Introduction

This chapter provides fax software developers with specific Class 2 fax command protocol information to be used in development with Lucent L33xVCS modem chip set. It is assumed that users have an understanding of ITU-TSS T.30 and T.4 concepts. The “fax command protocol” is defined here as the set of AT Commands used to control the sending/receiving of faxes. The term “fax” is defined as a specialized file transfer protocol for transferring black and white bit mapped images.

AT commands are used to control parameters for this file transfer and to initiate a particular action in the fax protocol. They also provide responses to indicate the progress and status of the transfer.

Class 2 Fax Command Implementation

The MultiModems implement an extension to the AT Command set for controlling fax transmission and reception, which is in compliance with EIA proposed standard TIA-592 (August, 1990) as specified by EIA subcommittee TR29.2. It involves a set of new commands, responses and procedures.

Class 2 Fax Commands (EIA SP-2388 August 1990)

The Lucent L56xVCS Chip Set supports fax Class 2 (August ‘90) commands. These commands and short descriptions of the commands are provided below. For more detailed information, refer to the August 1990 proposal.

Note: The EIA SP-2388 August 1990 proposal is being updated and will be made available when completed.

+FAA	FAX Auto Answer Enable
Command Syntax:		+FAA=<value>
		0: Answer as FAX modem of type specified by +FCLASS
		2: Automatically determine whether to answer as FAX or data modem

+FAXERR	T.30 Session Error Report
Command syntax:		+FAXERR
Response syntax:		+FAXERR=<value>
		0 - 9	Call placement and termination
			0: Normal and proper end of connection
			1: Ring detected without successful handshake
			2: Call aborted, from +FK or <CAN>
		10 - 19	Transmit phase A and miscellaneous errors
		20 - 39	Transmit phase B hang-up codes
			20: Unspecified transmit phase B error
			23: COMREC invalid command received
			25: DCS sent 3 times without response
			27: Failure to train
		40 - 49	Transmit phase C hang-up codes
			40: Unspecified transmit phase C error

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