Motorola 326X V.34 User Manual page 116

326X Series Modem Troubleshooting Guide (Continued)
Problem Diagnosis/Test
Data is garbled or lost Check the modem's flow control
settings.
Check that the modem's DTE
rate, parity, and character length
match the DTE's settings.
If in normal mode, check line
quality:
Data stops passing Modem could be in "flow off"
condition (modem set for XON-
XOFF and DTE set for hardware
flow control).
The modem connects at Check CQMS parameters for
a lower rate than the line quality.
maximum (as set in the
*
Max Rate (AT MX)
option)
Ensure that the remote modem
supports the DCE rates you
anticipate.
Excessive modem Retry call.
retrains
6-6 Troubleshooting Guide
• Check CQMS parameters
(signal quality and error
probability).
• Run a remote digital
loopback (RDL) or RDL
with pattern test.
• If you are still receiving
errors, disconnect the
modem from the line and
perform a local analog
loopback (LAL) or LAL
with pattern test (with
modem flow control off).
Possible Solution
• Ensure that the DTE's flow control is the same as the
modem setting
(for example, XON-XOFF, RTS/CTS).
• If your communications package's file transfer pro-
tocol is used, and the package supports RTS/CTS
Flow control, set Flow=RTS/CTS (AT
package does not support RTS/CTS flow control, set
Flow=Off (AT * FL0).
If they do not match, adjust as necessary.
If no errors occur, the line is good.
If errors occur, perform a manual retrain, or retry the
phone call.
If the LAL or LAL with pattern test fails, contact Motor-
ola Customer Support.
If the LAL or LAL with pattern test passes, you may have
a line problem (contact your telephone company) or a
problem with your application (check with your software
vendor).
• Set the modem for hardware flow control.
*
• Set Flow=Off (AT FL0).
Line quality is not sufficient to support higher data rate. If
line quality improves, the modem will increase its speed
automatically.
Continuous retrains indicate a line problem. Contact your
telephone company.
* FL3). If the