Issue
The modbus RS485 connectors on the MPM-UN are marked MOD A & B, the documentation does not state the polarity.
Product Line
EcoStruxure Building Expert
Environment
MPM-UN
Modbus
Cause
Documentation does not state the polarity of the Modbus connectors.
Resolution
Connect the Modbus device to the A-B connectors on the MPM. Connect the positive lead to connector A and the negative lead to connector B.
