Appendix F-Modem Testing; Testing With &T; Ending A Test-&To, S18 - US Robotics COURIER User Manual

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COURIER HIGH SPEED MODEMS
APPENDIX F. MODEM TESTING
Testing is available with the &T command or Register 516. All
loopback testing conforms to CCITT Recommendation V.54.
Earlier U5Robotics high speed modems, however, did not
perform the & T test repertoire.
NOTE: Only one test can be performed at a given time. If you
send a test command while the modem is in test mode, you'll
receive an ERROR message.
TESTING WITH &T
The tests supported through the &T command include analog
loopback, digital loopback and remote digital loopback. Users
can key in their own data during testing, or use the modem's
internal test pattern and error detector.
In all cases, disable error control before testing. If the modem is
detecting errors and retransmitting the affected data, your
results will be invalid.
During testing, the MR status light flashes.
Ending a Test-&TO, S18
Issuing the &TO command terminates a test. Alternatively, set
Register 518 to a specified number of seconds, for example,
518=10. When the 10 seconds are up, the modem automatically
ends the test and returns to Command mode. If the test was
Analog Loopback, the &TO command hangs the modem up. If
the test was Digital or Remote Digital Loop back, issue an A TH
command to hang up the modem, or an ATZ command to hang
up the modem and reset it to its defaults.
NOTE: If you use the 518 test timer, but in the process of testing
you issue an ATZ command, 518 resets to zero and the timer is
disabled. You cannot store a value for 518 in nonvolatile
memory: its power-on and reset default is always zero.
Modem Testing F-1