Diag 2 Flash 5

Field Voltage Too Low

Beckhoff · EL2904 TwinSAFE Fail-Safe Output Terminal

What does Diag 2 Flash 5 mean?

The voltage supplied to the power contacts of the terminal is below the permissible operating range (24V -15%/+20%). This can be caused by the voltage not being switched on, being switched on after the terminal supply, being generally too low, or by a short-circuit at an output causing a voltage drop. This affects the overall operation of the terminal's outputs and can lead to unreliable behavior or shutdown of safety functions.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    Increase the voltage at the power contacts to within the specified range and reset the error display through PowerOn Reset.

  2. 4

    Eliminate any short-circuits at the outputs and check supply lines for excessive voltage drops, designing the power supply accordingly.

  3. 5

    Take suitable EMC measures if electromagnetic interference is suspected to be contributing to voltage instability. If the issue persists, replace the terminal.

Source: Beckhoff EL2904 TwinSAFE Fail-Safe Output Terminal
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