How to add or assign modbusSlave ID more than one

[pylon]

@hermanto_simanungkalit

arduino uno as slave and using RS 485 converter.

You shouldn't use the ArduinoModbus library on AVR Arduinos as it's designed for MKR Arduinos (which have a lot more RAM).

@hermanto_simanungkalit

  /*
    modbus registers follow the following format
    00001-09999  Digital Outputs, A master device can read and write to these registers
    10001-19999  Digital Inputs, A master device can only read the values from these registers
    30001-39999  Analog Inputs, A master device can only read the values from these registers
    40001-49999  Analog Outputs, A master device can read and write to these registers

    Analog values are 16 bit unsigned words stored with a range of 0-32767
    Digital values are stored as bytes, a zero value is OFF and any nonzer value is ON

  */

This is only a convention used by some PLC vendors. It's not part of the Modbus standard you can use any address for any type of register. Unfortunately some PLC vendors even don't use the higher register numbers but use the range only to select the type of register, so that 30001 effectively is input register 1.