Rockwell Automation 1747-L40 SLC 500 Fixed Hardware Style - Manual (Page 102)

Chapter 8
Troubleshooting
8–11
Corrective Action
If your Output
Circuit LED is
And Your Output
Device is
And Probable Cause Recommended Action
On/Energized
Your program
indicates that the
output circuit is off or
the output circuit will
Programming problem.
Check for duplicate outputs and addresses using the
search function.
If using subroutines, outputs are left in their last state
when not executing subroutines.
Use the force function to force output off. If this does
not force the output off, output circuit is damaged. If the
output does force off, then check again for
logic/programming problem.
the output circuit will
not turn off.
Output is forced on in program.
Check processor FORCED I/O or FORCE LED and
remove forces.
On
Output circuit is damaged.
Use the force function to force the output off. If this
forces the output off, then there is a logic/programming
problem. If this does not force the output off, the output
circuit is damaged. Try other output circuit. Replace
module.
Your output device
Low or no voltage across the
load.
Measure the source voltage and check specifications.
Off/De-energized
Your output device
will not turn on and
the program
Incorrect wiring or open circuit. Check wiring and COMmon connections.
Off/De-energized the program
indicates that it is
on.
Output device is incompatible.
Check specifications and sink/source compatibility (if
DC output). o
Output circuit is damaged. Check wiring. Try other output circuit. Replace module.
Output device is incompatible. Check specifications.
Your output device
will not turn off and
Output circuit Off-state leakage
current may exceed output
device specification.
Check specifications. Use load resistor to bleed off
leakage current. See output specifications.
On/Energized
will not turn off and
the program
indicates that it is
off
Incorrect wiring.
Check wiring. Disconnect from SLC and verify device
operation.
off.
Output device is shorted or
damaged.
Verify device operation. Replace device.
Output circuit is damaged. Check wiring. Try other output circuit. Replace module.
Off
Off/De-energized
Your program
indicates that the
output circuit is on or
the output circuit will
Programming problem.
Check for duplicate outputs and addresses using
search function.
If using subroutines, outputs are left in their last state
when not executing subroutines.
Use the force function to force output on. If this does
not force the output on, output circuit is damaged. If the
output does force on, then check again for
logic/programming problem.
the output circuit will
not turn on.
Output is forced off in program.
Check processor FORCED I/O or FORCE LED and
remove forces.
Output circuit is damaged.
Use the force function to force the output on. If this
forces the output on, then there is a logic/programming
problem. If this does not force the output on, the output
circuit is damaged. Try other output circuit. Replace
module.