User`s manual

U.S. Robotics I-modem Command Reference
Troubleshooting • Page 15-7
Connects at 64 Kbps or 56 Kbps, but canÕt pass data
Your telephone company may be providing incorrect connection speed information. Try
forcing the connection speed to 56 Kbps by sending ATS67.1=1 and ATS67.2=0. If you
still canÕt pass data, try forcing the connection speed to 64 Kbps by sending ATS67.1=1
and ATS67.2=1. Any problems will likely be conÞned to one phone number, so after the
call, change the setting back to auto-sense, ATS67.1=0.
Many CRC errors
¥ Send AT&F1 to enable hardware ßow control and other optimized settings.
¥ Try a different File Transfer Protocol (do not use XMODEM if other protocols are avail-
able to you)
¥ If you use memory-resident programs (TSRsÐTerminate and Stay Resident programs) or
disk-caching programs, they may be interfering. Try disabling them before you run your
com-muni-cations software.
Mainframe computer keeps dropping your connection
You must turn off the I-modemÕs result codes and character echo (ATQ1E0). The modem
at the mainframe also needs to be set to ATQ1E0.