Supply Voltage or Internal Temperature Out of Range

What does Diag3:off, Diag4:steady_lit mean?

This diagnostic LED state (Diag 3 off, Diag 4 steadily lit) indicates that either the supply voltage to the terminal or its internal temperature is outside the permissible operating range. More detailed information can be found by examining the diagnostic object FA00hex. This condition can lead to system instability, unreliable operation, or terminal shutdown.

• The supply voltage to the device is outside its specified operating range (too high or too low).
• Internal temperature of the device has exceeded its safe operating limits.
• Power supply unit or internal cooling system is malfunctioning.

Click steps to track your progress.

1. 1

   Measure the input supply voltage to the EL6900 terminal at its power terminals to confirm it is within the specified operating limits.

2. 2

   Check the diagnostic object FA00hex for specific temperature (0005, 0006, 0007 hex) or supply voltage (0101-0104 hex) sub-indices to pinpoint the exact issue.

3. 3

   Verify the ambient temperature around the EL6900 terminal to ensure it is within specified limits, checking for any localized heat sources or obstructions.

4. 4

   Inspect the EL6900 terminal and its immediate surroundings for proper ventilation and clear airflow paths.