Siemens SIMATIC ET 200S Manual page 409

Compensation by means of a resistance thermometer at the 2AI RTD
If thermocouples that are connected to the inputs of the 2AI TC have the same
reference junction, compensate by means of a 2AI RTD.
For both channels of the 2AI TC module, you can select "RTD" or "None" as the
reference junction. If you select "RTD," the same reference junction (RTD channel)
is always used for both channels.
2AI RTD parameterized to the
Pt100 climatic measuring range
Isolated thermocou-
ples with external
compensation by
means of a resistance
thermometer connec-
ted to the 2AI RTD
(channel 0).
Figure 13-3
ET 200S Distributed I/O System
EWA-4NEB780602402-09
2AI RTD
M+
M–
I
C+
I
C–
Compensation by means of the 2AI RTD
Analog Electronic Modules
2AI TC
Abbreviations used
M+: Measuring line (positive)
M–: Measuring line (negative)
I : Constant-current line (positive)
C+
I : Constant-current line (negative)
C–
M+
1 1
5 5
M–
2 6 2 6
3 7 3 7
4 8 4 8
13-25