Black Box MD1970A, Руководство пользователя

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Chapter 4
Troubleshooting
T
his chapter describes troubleshooting procedures you can use in the unlikely event you encounter a problem with
your modem.
Local Modem Test
The local modem test verifies the local modem’s transmitter, receiver, and connection to the locally attached DTE.
This test can be run either by generating a data pattern from the locally attached DTE or by having the modem
generate a test pattern.
The following procedure describes how to run the local modem test using a locally attached DTE to generate a data
pattern.
1.
Using the front panel test switch, place the modem in Analog Loopback mode.
2.
Turn on the Request To Send line.
3.
Use the locally attached DTE to transmit the data pattern and check for data errors on the Receive Data line.
The following procedure describes how to run the local modem test using the modem test pattern instead of a data
pattern originated by the local DTE.
1.
Using the front panel test switch, place the modem in Self Test mode.
2.
The TM indicator should turn ON. If the indicator turns OFF or flashes, errors are occurring.
Line and Modem Test
The line and modem test verifies the local modem, the remote modem, and the communications line between them.
With this test, the local modem loops back received data to the transmitter and transmits the data to the remote
modem. These characters can originate either from a locally attached DTE or by having the modem generate a test
pattern.
The following procedure describes how to run the line and modem test using a locally attached DTE to generate a
data pattern.
1.
Place the remote modem in Digital Loopback mode.
2.
Place the local modem in Data mode and transmit a data pattern. Check for data errors on the Receive Data line
The following procedure describes how to run the line and modem test using the modem test pattern instead of a
data pattern originated by the local DTE.
1.
Place the remote modem in Remote Test mode.
2.
Place the local modem in Remote Self Test mode. The TM LED should turn ON and remain ON if the data is
error free.
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