Omron SYSMAC CS Series Operation Manual page 240

Troubleshooting the Network
Problem
PROFIBUS Master Unit is
configured. Some, but not
all slaves exchange data.
Probable cause
Network cabling is not correct.
• BF LED indicator is ON or Flashing.
• Master Status 2 error flag may provide
more information (CIO Word n+6, bit 00 ~
03, see Note).
• CIO Words n+9 to n+16 show which
slaves have problems.
Configuration is not correct.
• BF LED indicator is Flashing.
• CIO Words n+9 to n+16 show which
slaves have problems.
• Use CX-Profibus and DTMs to determine
slave diagnostics.
The configuration contains timing errors.
• BF LED indicator is Flashing.
• Slaves are sometimes briefly in and out of
data exchange.
A second master device (with its own slave
devices) is on the same network, interfering
with this Master Unit.
• The baud rate settings of both masters is
different.
• The total Target Rotation Time set to both
masters is too small (i.e. not the sum of
both individual time values).
Specific slave devices are configured and
allocated to the Master Unit, but the slave
which is not exchanging data may have been
disabled using the FINS STOP command.
Correction
Verify that the network installation is correct:
• Verify that all slaves are powered up and
functioning correctly.
• Verify that all slave devices are correctly
connected to the network.
• Verify that any repeaters used are func-
tioning correctly.
• Check the cable length versus the
selected baud rate.
• Verify that any stubs used are not too
long.
• Verify that termination (resistors and
inductors) are properly set and used.
Verify that the configuration is correct:
• Verify that address of targeted slave
device matches the configured address.
• Verify that the slave parameter and config-
uration settings are correct.
• Verify that the watchdog setting for the
slave device is not too low.
• Increase slave Watchdog Control value in
the Master Unit Bus parameter set.
• Verify that the Bus parameter sets are cor-
rect. If necessary, increase Target Rota-
tion Time and/or Min. Slave Interval
parameters.
• Re-download the configuration.
• If the problem persists, replace the Unit.
• Verify that all masters on the network are
set to the same baud rate.
• Verify that the total Target Rotation Time
for all masters on the network is set to the
sum of all individual masters.
Use the FINS RUN command to enable the
slave devices.
Section 7-4
219