Filter
Top Products
COURIER HIGH SPEED MODEMS
H-8 Modem Testing
2. Bring the modem back to Command mode with the +++
escape code. Then send it the AT&T7 command. The
modem enters RDL mode and the MR status light flashes.
The modem sends its internal test pattern 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 automatically 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.
4. Reset DIP switch 9 OFF unless you normally operate with it
ON. Issue an ATZ command to initiate the new switch
setting. Reset the modem to &M4 unless you've sent it the
ATZ reset command.
TESTING WITH REGISTER S16
Register S16 is a bit-mapped register with the following bit
functions:
Bit Value Function
0 1 Analog Loopback (AL)
1 2 Dial Test
2 4 Test Pattern
3 8 Remote Digital Loopback (RDL)