What to do if the "RUN" LED is off and the "ERR" LED is off on Stahl Control Unit?
- Jjohn19Aug 18, 2025
If the "RUN" LED and the "ERR" LED are both off, it indicates that there is no supply voltage at the CPM or the CPM is defective. To resolve this: * Check the CPM's power supply. * Check the CPM and the BusRail. * Ensure the CPM is correctly engaged on the BusRail. * Replace the CPM if necessary.