Diagnostic LEDs
The four green RUN LEDs indicated the operating state of the terminal channels.

Meaning of the LED displays
LED | Color | Channel | State | |
---|---|---|---|---|
On | off | |||
Run1 | green | 1 | normal operation | A watchdog timer overflow has occurred. The green LEDs go out if no process data are transferred between the controller and the Bus Coupler for more than 100 ms. |
Run2 | 2 | |||
Run3 | 3 | |||
Run4 | 4 |