
Rockwell Automation Publication 856T-UM001B-EN-P - April 2021
75
Appendix
F
Troubleshooting
This appendix shows ways to determine the possible cause of the 856T-B24LC
module being in a faulted state or not operating properly. It describes the
procedures that you use to troubleshoot your module.
Error Resolution
IMPORTANT
The following table describes errors or conditions that may be
encountered after a successful Power On Self Test (POST).
For more information on POST test results, see
Error/ Condition
Possible Cause
Recommended Action
Internal status indicator on
856T-B24LC module does
not light up
Power supply switched off.
• Review that Power is switched ON.
• Check that connection IO-Link Master and 856T-B24LC module is properly made.
• Review physical integrity of the patch cord or cordset used (that is, free of cuts and
similar.)
Communication loss
(Green status indicator on
856T-B24LC module is not
blinking)
Cable between IO-link master and 856T-B24LC
module is loose or has been cut.
Check cable integrity and replace if necessary.
Voltage to the 856T-B24LC module is below
accepted limit levels
Check voltage that is supplied to the master and the 856T-B24LC module.
Light or sound modules do
not turn on.
No Class B power is applied to 856T-B24LC module. If the 856T-B24LC module is used with a Rockwell Automation Class A master, verify that
you are using the recommended patchcord. See
for more details.
Short circuit alarm is present.
Clear short circuit condition.
Open condition alarm is present
Check that all modules have been properly placed and twisted in the stack light.
Light/sound module malfunction.
Replace Light or sound module in the tower light.
Improper light or sound module configuration
Check that the light or sound module is configured correctly in AOP.
Short circuit indication
present
Light or sound modules present a short circuit.
• Disconnect power to the 856T-B24LC module.
• Physically replace the modules that show the short circuit condition.
• Power cycle the circuit where the fault was shown to clear the fault.
Performed a hot swap of light or sound modules in
the stack light.
• Always disconnect power to the 856T-B24LC module before replacing a light module.
• Reinstall the light or sound modules in the stack light.
• Power cycle the circuit where the fault was shown to clear the fault.
Multifunction light module
not working as expected
when internally configured
as flashing or strobe light
module.
Multi-function module is selected as steady light
with slow or fast flash in the AOP.
Change 856T-B24LC module configuration to multi-function module.
Invalid Device Status
Device status shown as maintenance required, out
of specification, or failure.
for more details.
Содержание Allen-Bradley 856T-B24LC
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Страница 72: ...72 Rockwell Automation Publication 856T UM001B EN P April 2021 Appendix D Device Status Notes ...
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