User`s manual

U.S. Robotics I-modem Command Reference
Testing • Page 14-1
Chapter 14
Testing
The I-modem can perform digital and remote digital loopback tests. You can use these
tests to check the operations of the transmitter and receiver, or to locate a problem with a
remote device or a telephone line.
Test by sending an &T command or by setting Register S16. Only one test can be per-
formed at a given time. If you send a test command while the I-modem is in test mode,
you'll receive an ERROR message.
All loopback testing conforms to ITU-T Recommendation V.54.
Note When the I-modem is in synchronous
mode (&M1, &M6, &M7), testing is
not available.