IBM 3746-900, Installation And Maintenance Manual

Page: 44 / 264

This operational message shows that the modem is set in AT command
mode for switched-line operation with error control enabled and will
auto-answer an incoming call.
In the next steps, you are instructed to manipulate the front panel buttons
of the modem. Unless the step suggests otherwise, do not press them in
for longer than 1 second.
The next step reset the modem options to the factory default
configuration 0. Jump ahead to step 7 if the modem has never been
used.
Step 6. Set the modem power switch to OFF, then hold the
↑
key pressed and
set the power switch to ON. When the message
SELFTEST RUNNING
is
shown, release the
↑
key.
After about 15 seconds the message is changed to:
AT CMD ec aa
td_ rd_ dsr_ II_
Figure 1-21. 7858 Operator Panel Display
If this sequence does not occur, the modem is defective and should be
replaced.
Step 7. The next steps can only be done if you have attached the modem to the
public switched network. Go to step 11 if you do not want to test the
modem’s public switched network interface.
Step 8. On the modem operator panel:
a. Press the
↑
until the
DTR (C108)
message is displayed on the top
row.
b. Press the
→
key until the Forced On message is displayed on the
bottom row.
c. Press Enter twice to select the option and to return to the modem
operational mode message.
Step 9. Dial the modem phone number from another telephone. You should hear
the ringing tones and then the 2100-Hz answer tone from the called
modem in the handset of the dialing telephone. If you hear the answer
tone, go to
step 11 . Otherwise, continue with step 10 .
Step 10. If you do not hear the modem answer tone, verify that the telephone line
is operating properly. In most countries, you can do this by replacing the
modem with a handset and then attempting a second time to dial the
modem phone number from another telephone to verify that the handset
rings properly.
Connect again the modem to the public switched network and try dialing
the modem phone number again. Observe the front panel OH light. This
light turns off when the modem answers. If this attempt to call the modem
fails, the modem is defective and should be replaced.
Step 11. Set the modem power switch to OFF.
Note: The following steps assume that your DTE is already installed
and operational.
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3745-XXA 1-24 3746-9X0: 6578 SPIM