Siemens simatic ET 200MP - Block Diagram and Pin Assignment for Voltage Measurement

Wiring
Analog Input Module AI 8xU/I/R/RTD BA (6ES7531-7QF00-0AB0)
14 Manual, 03/2019, A5E44792324-AA
Block diagram and pin assignment for voltage measurement
The example in the following figure shows the pin assignment for voltage measurement.
①
Analog-to-digital converter (ADC)
CHx
Channel or 8 x channel status (green/red)
②
Backplane bus interface
RUN
Status display LED (green)
③
Infeed element (for shielding only)
ERROR
Error display LED (red)
④
Equipotential bonding cable (optional)
Figure 3-2 Block diagram and pin assignment for voltage measurement