ActionTec 56K PCI Pro User Manual page 63

\Xn
Result Codes:
-Cn
Data Calling Tone is a tone of certain frequency and cadence as specified in V.25
which allows remote Data/FAX/Voice discrimination. The frequency is 1300 Hz with
a cadence of .5 s on and 2 s off.
Result Codes:
XON/XOFF Pass Through
Data Calling Tone
62