Siemens SENTRON 3WA1 Manual page 153

The following graphic shows the interconnection of the COM150 communications
module, a PSS COM, and an external write protection switch.
Connection X65 Modbus RTU
The COM150 communication module has a 3-pole connection X65 for the Modbus RTU
connection according to the EIA/TIA-485 standard.
The assignment of the poles is as follows:
• B / +
• A / -
• C (Common)
3WA1 air circuit breaker
Equipment Manual, 02/2023, 92310000002-06
2.8 Communication and system connection
Description
151