Beckhoff EL2904 Operating Instructions Manual page 33

4.4.1.3 Diag 3 (red) and Diag 4 (red)
If the Diag 3 LED is lit, the Diag 4 LED indicates internal terminal errors.
These errors lead to shutdown of the terminal. The terminal must be checked by Beckhoff Automation
GmbH.
Flashing Codes
In the case of such an error, the Diag 4 LED on the EL2904 displays flashing codes that describe the
error in more detail.
A flashing code consists of four sequences, which are interrupted in each case by a short break. After the
four sequences there is a long break, following which the flashing code is displayed again.
Count the individual sequences of the flashing code.
Note the flashing codes and return the terminal
Note the flashing code displayed and include this information with the terminal when
Notice
you return it.
EL2904
Operation
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