Siemens SIMATIC S7-1500 Manual page 22

Wiring
3.1 Wiring and block diagrams
Connection: Grounded thermocouples for internal compensation
The following figure shows an example of the pin assignment for grounded thermocouples
for internal compensation.
①
Wiring of a thermocouple (grounded) for internal
compensation
②
Analog-to-digital converter (ADC)
③
Backplane bus interface
④
Supply voltage via power supply element
⑤
Equipotential bonding cable (optional)
Figure 3-8 Block diagram and pin assignment for grounded thermocouple
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CHx Channel or 4 x channel status (green/red)
RUN Status display LED (green)
ERROR Error display LED (red)
PWR LED for power supply (green)
Analog Input Module AI 4xU/I/RTD/TC ST (6ES7531-7QD00-0AB0)
Manual, 09/2016, A5E32366209-AC