Siemens SIMATIC S5 1P 243 Equipment Manual page 24

Function Description
The following block diagram shows the operating method of the analog value conditioning circuit:
Front connector
Input time
constant
T
0.1 msec.
conditioning
Example:
An input voltage which can vary in the range from –1 V to –1.5 V is to be compared in terms of
hardware with an input voltage from –0.5 V to –2 V.
Both signals are routed through the analog value conditioning circuit. The following settings are
possible:
Offset = +2
Gain = 3
–1 .0 v x 0.5
–1.5 v x 0 , 5
–0.5 v x 0 . 5
x
– 2 . 0 v 0 . 5
Accordingly, the voltages 3.75 V to 4.5 V on one side are compared with 3.0 V to 5.25 V on the
other side.
There are many possibilities for setting the trimming potentiometers. The user decides which con-
version is most suitable.
3 – 12
O crating point
o set #
v
–2 to
Gain setting
v
+2
Multiplication constsnt
–
XO.5
–0.50 v
+2.00 v
x
.50 v 3 = +4.50 v
–0.75 v
+2.00 v
V 3 = +3.75 v
X
+2.00 v
+1 x 3 = +5.25
.75 v
+2.00 v
x 3 = +3.00 v
Analog signal
jumpering
x 1 to 10
AR13 toAR16
n
Measuring socket
1 to 4
V