Arduino ModbusRTU programming into Modbus TCP

[dpslusser]

So I found this code (below) on a forum and it works great for me.

The problem is that I want to get away from serial and go TCP.

Anyone with Arduino skills know how to change it to work with an Ethernet shield via TCP?

#include <modbus.h>

#include <modbusDevice.h>

#include <modbusRegBank.h>

#include <modbusSlave.h>



/* PINS

Add more registers if needed

Digital input pins 2,3,4,5,6,7

Digital output pins 8,9,12,13

Analog output pins 10,11 (PWM)

Analog input pins 0,1,2,3,4,5

*/





modbusDevice regBank;

modbusSlave slave;



int AI0,AI1,AI2,AI3,AI4,AI5;





void setup()

{   

  regBank.setId(1); ///Set Slave ID



//Add Digital Input registers

  regBank.add(10002);

  regBank.add(10003);

  regBank.add(10004);

  regBank.add(10005);

  regBank.add(10006);

  regBank.add(10007);

// Add Digital Output registers

  regBank.add(8);

  regBank.add(9);

  regBank.add(12);

  regBank.add(13);

//Analog input registers

  regBank.add(30001);

  regBank.add(30002);

  regBank.add(30003);

  regBank.add(30004);

  regBank.add(30005);

  regBank.add(30006);

//Analog Output registers

  regBank.add(40010);  

  regBank.add(40011);  



  slave._device = &regBank;  

  slave.setBaud(9600);   

  

  pinMode(2,INPUT);

  pinMode(3,INPUT);

  pinMode(4,INPUT);

  pinMode(5,INPUT);

  pinMode(6,INPUT);

  pinMode(7,INPUT);

  pinMode(8,OUTPUT);

  pinMode(9,OUTPUT);

  pinMode(12,OUTPUT);

  pinMode(13,OUTPUT);

   

}

void loop(){



  while(1){   

  //Digital Input

    byte DI2 = digitalRead(2);

    if (DI2 >= 1)regBank.set(10002,1);

    if (DI2 <= 0)regBank.set(10002,0);

    byte DI3 = digitalRead(3);

    if (DI3 >= 1)regBank.set(10003,1);

    if (DI3 <= 0)regBank.set(10003,0);

    byte DI4 = digitalRead(4);

    if (DI4 >= 1)regBank.set(10004,1);

    if (DI4 <= 0)regBank.set(10004,0);

    byte DI5 = digitalRead(5);

    if (DI5 >= 1)regBank.set(10005,1);

    if (DI5 <= 0)regBank.set(10005,0);

    byte DI6 = digitalRead(6);

    if (DI6 >= 1)regBank.set(10006,1);

    if (DI6 <= 0)regBank.set(10006,0);

    byte DI7 = digitalRead(7);

    if (DI7 >= 1)regBank.set(10007,1);

    if (DI7 <= 0)regBank.set(10007,0);

                                

  //Digital output

    int DO8 = regBank.get(8);

      if (DO8 <= 0 && digitalRead(8) == HIGH)digitalWrite(8,LOW);

      if (DO8 >= 1 && digitalRead(8) == LOW)digitalWrite(8,HIGH);

    int DO9 = regBank.get(9);

      if (DO9 <= 0 && digitalRead(9) == HIGH)digitalWrite(9,LOW);

      if (DO9 >= 1 && digitalRead(9) == LOW)digitalWrite(9,HIGH);

    int DO12 = regBank.get(12);

      if (DO12 <= 0 && digitalRead(12) == HIGH)digitalWrite(12,LOW);

      if (DO12 >= 1 && digitalRead(12) == LOW)digitalWrite(12,HIGH);

    int DO13 = regBank.get(13);

      if (DO13 <= 0 && digitalRead(13) == HIGH)digitalWrite(13,LOW);

      if (DO13 >= 1 && digitalRead(13) == LOW)digitalWrite(13,HIGH);

            

  //Analog input  ***READ Twice deliberately

    AI0 = analogRead(0);

    delay(10);

    AI0 = analogRead(0);

    regBank.set(30001, (word) AI0);

    delay(10);

    

    AI1 = analogRead(1);

    delay(10);

    AI1 = analogRead(1);

    regBank.set(30002, (word) AI1);

    delay(10);

    

    AI2 = analogRead(2);

    delay(10);

    AI2 = analogRead(2);

    regBank.set(30003, (word) AI2);

    delay(10);

    

    AI3 = analogRead(3);

    delay(10);

    AI3 = analogRead(3);

    regBank.set(30004, (word) AI3);

    delay(10);

    

    AI4 = analogRead(4);

    delay(10);

    AI4 = analogRead(4);

    regBank.set(30005, (word) AI4);

    delay(10);

    

    AI5 = analogRead(5);

    delay(10);

    AI5 = analogRead(5);

    regBank.set(30006, (word) AI5);

    delay(10);

        

  //Analog output 

    word AO10 = regBank.get(40010);

    analogWrite(10,AO10);

    delay(10);

    word AO11 = regBank.get(40011);

    analogWrite(11,AO11);

    delay(10);

        

  slave.run();  

  }

}

 

[ojz0r]

Modbus RTU is ancient serial based while TCP is new ethernet based. Its not just going to be like changing a parameter in the code. Either you need to find the TCP standard and rewrite the code, or simpler: Use google or ask the experts on the arduino forum.

 

[DeKemp]

You can try this library http://myarduinoprojects.com/modbus.html.
Though I don't know how well this one works. Its based on the mudbus library, that one I once used to communicate with a s7-1200.