3Com 56K manual If the modem This indicates Returns a value, Class 1 Fax Mode

Data and Fax Modes 3-5

If you are not sure whether your modem is in Data or Fax mode, use the AT+FCLASS? command

.

If the modem	This indicates
returns a value of
0	Data Mode
1	Class 1 Fax Mode
2.0	Class 2.0 Fax Mode.

Whenever the modem is reset using the ATZ command or by turning the power off and then on, it will reset to Data Mode.