3WL air circuit breakers
3.5 External CubicleBUS modules
3WL/3VL circuit breakers with communication capability - PROFIBUS
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System Manual, 03/2011, A5E01051353-02
Rotary coding switch
The position of the rotary coding switch selects the operating mode.
PROFIBUS
INPUT
PARAMETER
SWITCH
Figure 3-17 Digital input module
3.5.2.1
Parameter set changeover
There are two different parameter sets for the protection function in the ETU76B trip unit.
This protection function is necessary when switching between mains operation and
generator operation in the event of a power failure, and there is the possibility of all tripping
conditions changing.
Changeover
Changeover between the two parameter sets can be made by means of:
●
PROFIBUS DP communication
●
Display in the ETU76B
●
Digital input module
Since the CubicleBUS is an event-driven bus, the ETU76B trip unit switches to the other
parameter set when a changeover request is made via the CubicleBUS.
This means, if a changeover is made to parameter set B, for example, even though the input
on the digital input module is at "0" (parameter set A), the active parameter set in the trip unit
changes to parameter set B. Only when the input on the digital input module is set to "1" and
then back again to "0" is an event for changing to parameter set A initiated on the
CubicleBUS.
For this purpose, the first input on the module is used in the position "PARAMETER
SWITCH" of the rotary coding switch. If a "1" signal (LED on input 1 is yellow) is detected
there, changeover to parameter set B is signaled to the trip unit. If the input signal changes
back to "0", changeover to parameter set A is communicated and the LED at input 1 goes
out.