IBM Aptiva Handbook page 180

Table 14: Common modem commands
Code/Command Function
–Cn Enables or disables the data calling tone, a V.25 specified tone that permits discrimination between remote data, fax, and
voice signals.
n=0 Disables the data calling tone (default).
n=1 Enables the data calling tone.
+++ Escape sequence.
Return to command state.
+ES=6 Enables the synchronous buffered mode.
+FCLASS? Displays the current fax service class.* For example, the following responses typically indicate the following settings:
000 Data mode
001 Fax Class 1 mode
008 Voice mode
080 VoiceView mode
* The +FCLASS? command is not supported by the TSR program that is required for operating the modem in DOS mode.
+FCLASS=? Displays which class of fax commands the modem supports. The following responses indicate the following classes of fax
commands:
0,1 The modem supports Class 1 commands.
+FCLASS=n Sets the modem for class n operation:
n=0 Selects data mode.
n=1 Selects fax Class 1 mode.
+FTS=<n> Causes the modem to stop transmitting data, pause for n centiseconds, and then transmit an OK. (1 centisecond equals
10 milliseconds.) The number of centiseconds can be between 0 and 255.
+FRS=<n> Causes the modem to listen and wait for an n centisecond period of silence on the line. (1 centisecond equals
10 milliseconds.) At the end of this period, the modem transmits an OK. The number of centiseconds can be between
0 and 255.
164 Appendix C: Modem information