Festo CPX-CTEL4-M12-5POL Manual page 27

1. System overview, CTEL system
Festo P.BE-CPX-CTEL-EN en 1205NH
Monitoring of the load supply voltage (PL) takes place in the
devices and is passed on to the CTEL master module.
Since all connected devices use this LED, the display of an
error has priority over the display "OK" (LED lights up green).
The I-port at which the error occurred can be determined
through the FMT/MMI using the diagnostic messages.
Information on eliminating the displayed errors can be found
in section 4.2.2.
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