Specifications
Table of Contents 
Multi-Tech Systems, Inc. SocketModem MT5600SMI/MT5656SMI Reference Guide (S000306B)  3 
Contents 
Chapter 1 – AT Commands, S-Registers and Result Codes.................................................................... 4 
Introduction................................................................................................................................................ 4 
Escape Code Sequence – +++ ................................................................................................................. 4 
Data Commands........................................................................................................................................ 5 
Generic Modem Control Commands .....................................................................................................5 
DTE-Modem Interface Commands.......................................................................................................... 11 
Call Control Commands .......................................................................................................................... 16 
Modulation Control Commands............................................................................................................... 26 
Error Control Commands......................................................................................................................... 30 
Data Compression Commands ............................................................................................................... 35 
V.8/V.8bis Commands............................................................................................................................. 38 
Diagnostic Commands ............................................................................................................................ 40 
Example Modem Response and Usage ..............................................................................................44 
Compatibility Commands......................................................................................................................... 45 
Fast Connect Commands........................................................................................................................ 46 
V.92 +P and –Q Commands ................................................................................................................... 47 
S-Registers.............................................................................................................................................. 51 
Result Codes ........................................................................................................................................... 59 
Chapter 2 – Fax Class 1 Commands......................................................................................................... 62 
Fax I/O Processing.................................................................................................................................. 62 
DTE-to-Modem Transmit Data Stream................................................................................................62 
Modem-to-DTE Receive Data Stream.................................................................................................62 
Fax Mode Selection .............................................................................................................................63 
Fax Origination.....................................................................................................................................63 
Fax Answering .....................................................................................................................................63 
Fax Control Transmission....................................................................................................................63 
Fax Control Reception .........................................................................................................................64 
Fax Data Transmission........................................................................................................................65 
Fax Data Reception .............................................................................................................................65 
Commands and Parameters ................................................................................................................... 66 
Mode Entry Commands .......................................................................................................................66 
Mode Commands.................................................................................................................................66 
Service Class 1 Commands .................................................................................................................... 70 
Examples................................................................................................................................................. 74 
Chapter 3 – Fax Class 2 Commands......................................................................................................... 76 
Command and Syntax Guidelines........................................................................................................... 77 
Mode Entry Commands .......................................................................................................................77 
DTE Commands ..................................................................................................................................77 
Serial Port Speed and Flow Control ....................................................................................................78 
Auto Answer.........................................................................................................................................79 
Identification of T.30 Options...............................................................................................................79 
Session Status Reporting ....................................................................................................................79 
Procedure Interrupt Negotiation...........................................................................................................79 
Service Class 2 Identification and Selection ........................................................................................... 80 
Service Class 2 Action Commands......................................................................................................... 81 
Service Class 2 DCE Responses............................................................................................................ 88 
Service Class 2 Parameters.................................................................................................................... 91 
Example Sessions................................................................................................................................... 95 
Chapter 4 – Voice Commands................................................................................................................... 97 
Voice Commands Overview .................................................................................................................... 97 
<DLE> Shielded Event Codes Sent to the DTE ..................................................................................98 
<DLE> Shielded Codes Sent to the Modem (DCE).............................................................................99 
Voice Configuration Commands............................................................................................................100 
Basic Voice Commands ........................................................................................................................ 101 
Index........................................................................................................................................................... 112 










