25.03.2025, 14:45
(25.03.2025, 14:40)admin Wrote: LM has GND connection next to RS485 A/B. Some Modbus devices have 0V connection. If yours don't you can use DC power supply input negative pole / GND.The Modbus slaves are energy meters powered by 230 volts, I have no GND reference, I only have the negative of the serial line.