Analog Value Conditioning Circuit; Operating Elements; Functioning - Siemens SIMATIC S5 1P 243 Equipment Manual

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Analog Value Conditioning Circuit

3.5

3.5.1 Operating Elements

The four inputs of the analog value conditioning circuits are meant to standardize the voltages
provided by encoders to the O V to +10 V range, and are conditioned in accordance with the set-
ting of the trimming potentiometer on the module front plate. Conversion in the O to +10 V range is
not possible unless input voltage > –4 V. Conditioning is always necessary when negative volt-
ages are processed and routed via the comparators. The
comparators are designed for positive voltages so that the input voltages must be transformed to
the positive range.
In addition to the 4 trimming potentiometers for setting the amplification and the offset, there are
four measuring sockets on the front plate via which the conditioned analog values can be
scanned. A socket (socket 6) is also available. This socket is connected to analog ground M
This socket can be used as the ground connection for a graphic recorder which records the condi-
tioned analog signals.
Attention: Socket5 hasnofixed internal connection toaspecificsignal. Itis located
on the analog–signal jumpering space AR32. This socket is free for
switching, either for a signal from an 1P 243. The conditional socket (i.e.,
the component routed to the soldering base) or for another external sig-

3.5.2 Functioning

On the front plate of the 1P 243 there is one trimming potentiometer per input (AV1 to AV4) for the
offset of the operation point by a binary amount between –2 V and +2 V and for setting the amplifi-
cation (gain) as a factor in the range from 1 to 10.
First, the active analog value is multiplied by the fixed factor 0.5 specified by the module. Then, the
set offset is added, and finally this value is multiplied by the desired gain factor. The possible total
gain is between 0.5 and 5.
Function Description
a.
ari
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