Rockwell Automation 1747-L40 SLC 500 Fixed Hardware Style - Manual (Page 101)

Chapter 8
Troubleshooting
8–10
The following will assist you in troubleshooting your output modules.
Output Circuit Operation
An output circuit controls the output signal in the following manner:
1. The processor determines the output status.
2. Logic circuits maintain the output status.
3. An output LED indicates the status of the output signal.
4. Optical isolation separates logic and backplane circuits from field signals.
5. The output driver turns the corresponding output on or off.
Processor
Optical
Isolation
Logic Circuits Output Drivers
LED
Output
Troubleshooting Your Output
Modules