3.1.7.5 Supply voltage status

There are two green LEDs in the coupler supply section to display the supply voltage. The left LED (A) indicates the 24 V supply for the coupler. The right hand LED (C) signals the supply to the field side, i.e. the power jumper contacts.

3.1.8 Fault behavior

3.1.8.1 Fieldbus failure

A fieldbus failure is given i. e. when the network manager (PC with Network Management Tool Software) cuts-out or the bus cable is interrupted. A fault in the network manager can also lead to a fieldbus failure.

For the LON fieldbus coupler the fault code and the fault argument are transfered by network variables or explicite messages.

3.1.8.2 Internal bus fault

An internal bus fault is created, for example, if an I/O module is removed. If this fault occurs during operation, the output modules behave in the same manner as an I/O module stop.

The "I/O" LED blinks red.

The coupler generates a fault message (fault code and fault argument).

Once the internal bus fault is fixed, the controller starts up following power being cycled as during a normal start-up. The transfer of the process data is then resumed and the node outputs are correspondingly set.

Modular I/O System

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