ZyXEL Communications U-336R/RE manual Extended Fax AT Command Set, Fax Operation

Extended Fax AT Command Set

Extended Fax AT Commands are unique to ZyXEL modems. The computer controls the modem through a set of extended fax AT commands and the modem responds with a set of status report result codes. During data state, compressed fax image data is flowing between the modem and computer. The default serial connection speed is 38400 bps, and it is higher than the fax link rate. CTS/RTS hardware flow control is used to regulate the data flow.

Your modem accepts the extended fax AT commands to set the modem mode and fax parameters. Besides the extended fax AT commands, the modem accepts all the other AT commands described in this chapter. For instance, you can use ATD to make a fax call, or ATA to answer an incoming fax call. When using the extended Fax AT commands, you need to send the command AT+FCLASS=6 first. Following are the fax related AT commands:

Mode Settings

Command	Function
#F	Set the modem into V.17G3 FAX mode. Same
	function as the extended AT command AT&N32.
#B0	Set fax receiving mode. The connection parameters
	and received fax data are sent to the DTE
	continuously following the connect message.
	(Default)
#B1	Set fax receiving mode. The messages are separated
	from the received fax data. The modem sends
	CONNECT FAX and ZyXEL first, then it waits for
	the DC2 character (hex18) to send the fax data.
	When the modem receives a DC2 from the DTE, it
	starts to send the fax connection
	parameters/SnnnnVnTnRnLnCnP<string><CR><LF
	> then the received fax data. In this mode, the

70 Fax Operation