Evaluation Of 24 V Digital Signals - Siemens SITRANS DA400 Operating Instructions Manual

Figure 7-3 Universal input function diagram
7.2.3

Evaluation of 24 V digital signals

Relates to following parameters
Parameter no.
P.26 to P.29
Evaluation
The electrical (voltage) signal is converted into a current by a multiplier and measured. This
is described in the "Evaluation of analog current signals" section. A comparator then uses
this value to determine the Low or High level for the signal. The threshold value is set so that
a normally open contact also generates a High signal via the 8.2 V source. With the
parameter setting "¬24 V", the digital signal is inverted.
SITRANS DA400 for oscillating positive displacement pumps with protection against explosion
Operating Instructions, 10/2007, A5E00841127-01
Parameter name Adjustment/display
range
"INP1" to "INP4" "24V" and
"¬24V"
Signal processing
7.2 Evaluation of universal inputs
Remark
24 V-Digital signal >7 V -> High
¬24 V-Digital signal <4.5 V -> High
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