Connecting Resistance Thermometers In The Extended Pt 100 Range - Siemens S5-155U System Manual

9.3.11
Connecting Resistance
Thermometers in the
Extended Pt 100 Range
System Manual
C79000-B8576-C109-03
The series-connected resistance thermometers (up to 8 Pt 100s) are fed
with a current of 2.5 mA (I
C+
voltage at the Pt 100s is picked off at measurement inputs M+ and M-.
In this mode, the temperature range of approximately -100 °C to
+100 °C has a more accurate resolution. The mode is printed on the
cover of the module as follows:
"resistance thermometer compensated low range".
You should only use the 6ES5 498-1AA11 range card (± 50 mV /
500 mV).
Unused inputs must be connected in parallel to a wired input. In the
following figure, for example, these are the inputs CH4 to CH7.
24V
M24V
Figure 9-10 Connecting Resistance Thermometers in the Extended
Pt 100 Range
The 460 Analog Input Module
/I ) by a constant current generator. The
C-
M+
6ES5 498-
Ch 0
M - 1AA11
M+
Ch 1
M -
M+
Ch 2
M -
M+
Ch 3
M -
M+
6ES5 498-
Ch 4
1AA11
M -
M+
Ch 5
M -
M+
Ch 6
M -
M+
Ch 7
M -
Ic -
Ic +
2,5 mA
L +
L -
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