02/2014
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37
Analogue output in the event of fault:
Function
Ranking
Definition
alarm value
The output signal jumps to the alarm value defined in the
analogue output
mask!
frozen value
The output signal remains at the value before fault
occurrence and is in an offline mode!
instantaneous
value
The output signal is updated and in online mode, but can
be erroneous!
Relay and transistor outputs in the event of fault:
Function
Ranking
Definition
on
The alarm output is switched on and the device required maintenance!
off
The alarm output is switched off!
lim-prio
The alarm output is switched off, only there is no limit value alarm.
limit
The alarm function is only the limit value monitoring!
Truth table for limit values and maintenance alarm:
Function
Limit value alarm
Maintenance
alarm
Alarm output
Notes
on
x
on
on
Only the fault alarm switched
the alarm output!
off
x
on
off
The fault alarm switches off
the limit value alarm!
lim-pro
x
on
off
The fault alarm switches off
the limit value alarm, but not
an existing limit value alarm!
on
(alarm exists!)
on
on
limit
off
x
on
Only the limit value alarm
switched the alarm output
on
x
off
x=optional (on or off)
With a fault occurrence, the behaviour of the analogue output and alarm outputs correspond
to the parameterization in the mask
System controlling
without taking account of the
ranking. After the occurrence of a second fault the highest rank of the functions involved
determines the behaviour of the analogue output and alarm outputs.
(See some examples on next page)
