Omron CJ Series Operation Manual page 252

7 Troubleshooting and Maintenance
Problem
PROFIBUS Master Unit
is configured. Some, but
not all slaves exchange
data.
7-20
Probable Cause
Network cabling is not correct.
• BF indicator is ON or Flashing.
• Master Errors flag may provide more
information (*_MstrBusErr,
*_MstrProtErr, *_MstrAdrErr,
*_MstrHwErr).
• Slave Data Exchange Active Flags
show which slaves have problems.
Configuration is not correct.
• BF indicator is Flashing.
• Slave Data Exchange Active Flags
show which slaves have problems.
• Use CX-ConfiguratorFDT and DTMs to
determine slave diagnostics.
The configuration contains timing errors.
• BF 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.
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
Correction
Verify that the network installation is cor-
rect:
• Verify that all slaves are powered up
and functioning correctly.
• Verify that all slave devices are cor-
rectly 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 con-
figuration 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
correct. If necessary, increase Target
Rotation Time and/or Min. Slave Inter-
val 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.
Enable the slave devices.