Total Control MP/16, Operator'S Manual

Page: 157 / 182

Modem Testing E-7
Establish a connec tion with the remote modem. If you haven't
already done so, arrange with the remote user to cooperate
with your testing and, if necessary, set the remote modem to
acknowl edge the RDL request. For example, older U.S.
Robotics high speed modems need to be set to S16=8.
2 Bring the modem back to Command mode with the +++ escape
code. Then send it the AT&T7 com mand. The modem enters
RDL mode and the Modem LED glows green.
The modem sends its internal test pat tern to the remote
modem, which loops it back to your modem. You will not see
the data on your screen.
3 End the test. If you set S18, the modem automati cally stops the
test when the timer times out. If you didn't set Register S18,
type AT&T0 to end the test. Or send either ATH or the
command that resets the modem, ATZ. The latter two
commands end the test and hang up the modem. The modem
responds OK. If you issue an invalid command, the modem
sends an ERROR message.
When you terminate the test, the modem returns a three-digit
code, followed by OK. A code of 000 indicates no errors were
found. A code of 255 indicates 255 or more errors.
If you've performed an Analog Loopback and know your
modem is working properly, errors indicate a problem with
either the phone connection or the remote modem.