IMPORTANT:

This assumes the Telebit is in CCM (Conventional Command Mode).
To place your modem into CCM, follow these steps:

  1. Turn the modem off.
  2. Hold in the T/D switch and turn the power on.  Release the switch 
     when the PEP,CD and MR lights are flashing.  Ignore any other lights 
     that may be lit from here on.
  3. Tap the T/D switch until just the CD light is lit (not flashing).  
     The PEP and MR lights are OFF.
  4. Press and hold the T/D switch (2 seconds or  more) until the CD light
     is flashing again.

                           OTHER NOTES:

Our configuration attempts a PEP connect first which which is the factory
default but the calling modem may need to set their S7=60 to connect due
to the extra time required to connect.  The dialing timeout parameter in
the com program should also be set to 60.
     
Your Telebit manual mentions that if you set ~S92=1 the modem will attempt
a PEP last which will make normal modems connect faster but another T2500
will need its S50 set to 255 to connect in PEP mode.

This configuration was tested with another T2500 and a USR DS v.32bis, were
able to connect at 300-9600.  The T2500 also connected in FAST mode which
we defined as 19200 in Makewild.