8-1-1-1

Exceeded Temperature Difference Between Measuring Points

Beckhoff · EL1904 Digital Input Terminal

What does 8-1-1-1 mean?

The EL1904 terminal has detected an excessive temperature difference between its internal measuring points. This can indicate uneven heating or cooling within the terminal, possibly due to poor installation, restricted airflow, or proximity to a localized heat source. This condition can lead to thermal stress on components.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    Compare the measured ambient temperature to the permissible operating temperature range specified in the terminal's technical data sheet.

Source: Beckhoff EL1904 Digital Input Terminal
Open Manual (Page 40)