Some Beckhoff i/o terminals are not active and status LEDs are off, control does not respond to commands.
Possible Causes & Resolutions:
- The 24Vdc supply of the EK1100 coupler or the EL9410 intermediate supply terminal is missing or the voltage is too low > Check all connections, measure voltage, check fuses.
- Bad contact between the terminals > Switch off the main power and remove the terminals. Clean the contact between the terminals.
- Defective EL9410 intermediate supply terminal > Exchange terminal.
- Defective EK1100 coupler > Exchange coupler.