3Com 56k User's Manual And Reference page 75

Fax Commands
+FTM=n Transmits data using the modulation specified by n
(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)
Note: See the "Screen Messages" table at the end of this section for an explanation of
messages that appear in response to this command.
+FRM=n Receives data using the modulation specified by n
(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)
Note: See the "Screen Messages" table at the end of this section for an explanation of
messages that appear in response to this command.
+FTH=n Transmits data framed in the HDLC protocol using the modulation specified by n
(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)
Note: See the "Screen Messages" table at the end of this section for an explanation of
messages that appear in response to this command.
+FRH=n Receives data framed in the HDLC protocol using the modulation specified by n
(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)
Note: See the "Screen Messages" table at the end of this section for an explanation of
messages that appear in response to this command.
Technical Reference
(Continued)
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