I am trying to perform the acquisition of data from an ABB inverter (PRO-33) with MAX485 with the arduino as master. I have already tested the TX / RX ports of the inverter with a USB-RS485 adapter and I can get the data perfectly using a SCADA. But when I test the code with the same Modbus parameters with arduino I get the error 0xE0 (ModbusMaster invalid response slave ID exception). The ID I am using is the same as that shown on the inverter monitor and for which I was able to obtain the data with SCADA … I don’t understand why this error appears! Mainly because I tested the code with the Modbus Tools simulator as a slave and I was right.
- I connected the A and B of the inverter to A and B of the MAX485. On the arduino I placed the DI and RO pins on TX1 and RX1, respectively. And pins RE and DE on 2 and 3.