This time I have communicated the Arduino with Panasonic PLC and I checked the Arduino useful in the industrial field direfencia of the previous tutorials I’ve tested both devices communicating via RS – 232.
1. The arduino send via modbus ADC value 0 to Holding Register 0 and the plc into a strategy compared as follows Arduino
If ADC> 500
relay output PLC = 1
PLC relay output = 0
2. The PLC send the value 2 of its potentiometers from 0 to 1000 and displayed on the display arduino Oled, the respective values
Programmable Logic Controller used in industrial in this case the family FPX panasonic (Aromat – Nais)
This PLC has Modbus RTU protocol as master and slave To configure a teacher must create a strategy, if set as slave does not require code as the default plc is a slave and records are automatically routed.
DT0 = Holding Register 
DT1 = Holding Register 
The control strategy of these PLC is done in the FPWIN Pro software:
Serial Ports settings
The arduino is configured as RTU Master to read and write 10 – 10 Holding Registers
Part 1 Arduino Modbus RTU Master
Video Final Test With Panasonic PLC
Github Code ARDUINO