US Robotics 56K Series Manual page 89

Register Default
S18 0
S19 0
S20 0
S21 10
S22 17
S23 19
S24 0
Function
Test timer for &T loopback testing
Sets the time in seconds of testing before the modem automatically
times out and terminates the test
When set to 0, the timer is disabled
Valid range is 1-255
Sets the duration, in minutes, for the inactivity timer
The timer activates when there is no data activity on the phone line; at
time-out the modem hangs up
S19 = 0 disables the timer
Reserved
Sets the length, in 10-millisecond units, of breaks sent from the
modem to the computer; applies to MNP or V.42 mode only
Stores the ASCII decimal code for the XON character
Stores the ASCII decimal code for the XOFF character
Reserved
83