I have been playing around with Modbus RTU library on the Arduino and use an Xbee Pro radio and able to read Modbus registers just fine.
I decided to build a second slave but having problems talking to both slaves. If i turn off either slave, I have no problems communicating.
One is address as Slave Id #1 and the other Slave Id#2.
Testing the slave with a Modbus Master the Arduino Slave seems to ignore requests addressed to any slave ID except the ID set in the Arduino.
The Xbee Radio's are programmed (Routers and Coordinator in AT) mode. Many to one configuration.
I assumed only the slave with the proper Slave ID would respond since the Coordinator only polls one slave at a time.
Does anyone know of a Modbus Library for the Arduino that allows multiple slaves on a serial network?
Anyone have a simple sketch / library or idea's why this isn't working.
The library I have tested are "Modbusino" and Modbus Slave downloaded from https://sites.google.com/site/jpmzometa/arduino-mbrt