Multi-Tech Systems MT3334SMI manual Class 1 Fax Command Summary, Command Description

ModemModule Developer’s Guide

Introduction

The Service Class 1 standard (EIA/TIA-578) defines the commands that a PC user may issue to configure and control a fax/data modem, and the responses (result codes) that the fax/data modem may issue in response to those commands.

The Class 1 standard provides the basic services needed to support Group 3 fax operation. Support of the 1988 CCITT (ITU-T) T.30 recommended procedures for session management and the T.4 recommendation for image data handling are required at the PC.

Service Class 1 provides the following services (as required, or optional in Group 3 facsimile operation):

•Connection (originate and answer),

•Waiting and silence detection,

•Data transmission and reception (data transfer),

•HDLC (High-level Data Link Control) data framing/transparency/error detection, and

•Message generation/response.

HDLC is an ISO standard, bit-oriented data communications protocol. HDLC control information is consistently placed, and specific control bit patterns are considerably different than those used as data, providing a largely error-free protocol.

Class 1 Fax Command Summary

The ModemModule Fax Class 1 enhancements are implemented with six AT+F (for Fax) commands. The +FTM, +FRM, +FTH, and +FRH commands must be entered as the last command in the command string (i.e., the last command on the command line). The +FTS and the +FRS commands can be entered anywhere in the command string.

Command Description

+FCLASS? Display Current Class

+FCLASS=? Display Service Class Capabilities +FCLASS=<> Select Service Class

+FTS=<time> Stop tranmission and pause (10 ms intervals, 0-255)

+FTS=? Display the valid +FTS=<time> range (0-255) +FRS=<time> Wait for silence (10 ms intervals, 0-255)

+FRS=? Display the valid +FRS=<time> range +FTM=<MOD> Transmit data with specified <MOD> carrier

+FTM=? Display the valid +FTM=<MOD> carrier range +FRM=<MOD> Receive data with specified <MOD> carrier

+FRM=? Display the valid +FRM=<MOD> carrier range +FTH=<MOD> Transmit HDLC data with specified <MOD> carrier

+FTH=? Display the valid +FTH=<MOD> carrier range +FRH=<MOD> Receive HDLC data with specified <MOD> carrier

+FRH=? Display the valid +FRH=<MOD> carrier range

If entering multiple commands on the command line, use semicolons between commands. These +F commands are defined in the following sections. The <MOD> parameter may take on the following values.

32 MT3334SMI