ZyXEL Communications U-336R/RE manual Class 1 Command Set, Fax Operation

Class 1 commands control on-line modem negotiation while Class 2 commands allow the modem to do many negotiations simultaneously. The Class 1 protocol uses the modem to transmit fax data only. The complete organizational overhead for this protocol is handled by the connected computer. The Class 1 command set is also called the TIA-578 standard.

Several revisions of the class 2 standard exist. Implementations conforming to different revisions may not work together. A formally approved version is the Class 2.0 command set, also called the TIA-592 standard.

Class 1 Command Set

Command	Value	Description
+FCLASS=n		Service class selection.
	n=0	Set to Data mode.
	n=1	Set to Class 1 mode.
	n=2	Set to Class 2 mode.
	n=2.0	Set to Class 2.0 mode.
	n=6	Set to ZFAX mode.
	n=8	Set to Voice mode.

ONOTE: IF S57.4=0 (DEFAULT), THE RESPONSE TO THE +FCLASS=? COMMAND WILL NOT REPORT CLASS 1 CAPABILITY. THIS IS DUE TO THE FACT THAT SOME FAX SOFTWARE PACKAGES MAY GET CONFUSED BY THIS RESPONSE.

Command	Value	Description
+FTS=n	0-255	Stop transmission and pause, in 10 ms

Fax Operation 55