Mounting and connecting
4.5 Electrical connections
SIPROCESS UV600
Operating Instructions, 10/2013, A5E03529375-02
37
Switching logic
●
Normal – open-circuit principle:
The digital output is electronically active (the relay is pulled-up) if the associated
switching function is logically active.
●
Inverted – closed-circuit principle:
The digital output is electronically active (the relay is pulled-up) if the logical switching
function is not active. In the logically active state, the digital output is electronically
deactivated (the relay is dropped-out).
Note: This version should be particularly checked if the output is to be used for a warning
signal.
Safety criteria
CAUTION
Risk for connected devices/systems
Clarify the safety consequences in the event of the following malfunctions before using the
switching outputs:
•
Power supply failure (e.g. local failure of power supply, inadvertent switch-off, blown
fuse)
•
Fault in input/output module (e.g. electronic fault of a switching output)
•
Interruption in the electric connection
Note the switching principle:
•
In the event of a power supply failure, switching outputs with normal switching logic
signal signal the switching function as not active.
•
In the event of a power supply failure, switching outputs with inverted switching logic
immediately signal that the associated switching function is tripped.
Carefully clarify the consequences, and ensure that a dangerous situation cannot occur in
the event of a fault or failure.