User Manual
Modems Troubleshooting
9-17
All data is corrupted. The ground pins aren’t wired
correctly.
Verify the wiring. Ensure that the ground pins on the
RJ45 ports are wired together.
The modem’s serial speed does not
match the serial speed on the SCS
port used.
Ensure that the serial speeds of the modem and SCS
port match.
Flow control isn’t working properly. Ensure that the modem and SCS port are configured
to use the same flow control method.
The modem is set to the wrong baud
rate.
Cycle power on the modem.
The first few lines of
data are transmitted
properly, but the
subsequent data is
corrupted.
Flow control isn’t working properly. Ensure that the modem and SCS port are configured
to use the same flow control method. Flow control is
discussed in detail in Flow Control on page 8-18.
The ground pins aren’t wired
correctly.
Verify the wiring. On RJ45 ports, ensure that the
ground pins are wired together.
When the port is logged
out, the modem doesn’t
hang up the phone line.
Modem Control isn’t enabled on the
SCS port used.
Ensure that Modem Control is enabled. See Define
Ports Modem Control on page 12-97 for details.
The DTR signal isn’t attached. Verify the wiring. Ensure that the ground pins on
RJ45 ports are wired together.
The modem isn’t configured to reset
when the DTR signal is dropped.
Check the modem’s configuration.
When the phone is
hung up, the SCS
doesn’t log out the port.
Modem Control isn’t enabled on the
SCS port used.
Ensure that Modem Control is enabled. See Define
Ports Modem Control on page 12-97 for details.
The DCD signal isn’t attached. Verify the wiring. Ensure that the ground pins on
RJ45 ports are wired together.
The modem isn’t configured to
deassert DCD upon loss of carrier.
Check the modem’s configuration.
The modem answers,
but won’t connect to the
remote modem.
One or both modems are configured
not to connect unless some feature
is enabled (for example, error
correction).
Check the documentation for both modems; verify
their configuration.
The two modems cannot be
connected. (Some modems are
incompatible with one another.)
Replace one or both of the modems. Verify that the
modem is using the correct and current version of its
software.
Table 9-3: Modem Troubleshooting, cont.
Problem Possible Cause(s) Remedy