Troubleshooting your output modules – Rockwell Automation 1747-L5xx SLC 500 Modular Hardware Style User Manual User Manual
Page 166

Publication 1747-UM011G-EN-P - June 2008
166
Troubleshooting
Troubleshooting Your Output Modules
If your
Output
Circuit
status
indicator
is
And your output
device is
And
Probable Cause
Recommended Action
On
On/energized
Your program
indicates that the
output circuit is
off or the output
circuit will not
turn off.
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.
Output is forced on in
program.
Check processor FORCED I/O or FORCE status indicator and
remove forces.
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.
Off/de-energized Your output
device will not
turn on and the
program
indicates that it
is on.
Low or no voltage
across the load.
Measure the source voltage and check specifications.
Incorrect wiring or
open circuit.
Check wiring and COMmon connections.
Output device is
incompatible.
Check specifications and sink/source compatibility (if dc
output).
Output circuit is
damaged.
Check wiring. Try other output circuit. Replace module.