Specifications

Chapter 12 – FAX Commands
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 168
Chapter 12. FAX Commands
The following commands can be used for FAX transmission. If the ME is acting as a Fax modem for a PC-based
application (e.g., “WinFax”), it is necessary to select the proper Service Class (Fax Class) provided by the ME.
The ME reports its Service Class capabilities, both the current setting and the range of services available. This is
provided by the AT+FCLASS command.
Service Classes supported by the ME:
AT+FCLASS Parameter Service Class Reference, Standard
0 Data Modem TIA/EIA-602 or ITU V.250
1 Service Class 1 EIA/TIA-578-A
12.1 FAX Parameters
Parameter Description
<mod>
Modulation Mode
24 V.27ter - 2400 bps
48 V.27ter - 7200 bps
72 V.29 - 7200 bps
96 V.29 - 9600 bps
Note: Only the default value needs to be implemented. Use the test commands to check which parameter
values are really possible.
12.2 AT+FCLASS Fax: Select, Read or Test Service
Class
Description: AT+FCLASS sets the ME to a particular mode of operation (data, fax). This allows the ME to
process information in a manner suitable for that type of information.
Test Command Syntax: AT+FCLASS=?
Response: (list of supported <n>s)
OK
Read Command Syntax: AT+FCLASS?
Response: <n>
OK
Write Command Syntax: AT+FCLASS=<n>
Response: OK
Parameter Descriptions:
<n>
0 Data. Default.
1 Fax class 1 (Service Class 1)
Notes:
• Using Error Correcting Mode (ECM) when sending FAXes over GSM should be avoided.
• If <n> is set to 1, all incoming calls will be answered when ATA is issued on multiplexer channel 1 resp. ASC0.
For calls explicitly signaled as voice or data calls, this procedure will fail with result code “NO CARRIER”, but the
incoming call will continue to ring.
It is possible to change the setting of <n> to 0 while the call is ringing, and accept the call normally afterwards
with ATA.