I am trying to implement Modbus TCP on arduino uno + ethernet shield using the following code. I am using a modbus slave simulator on a pc to check the following code. However, the code doesn’t seem to be working. I have downloaded the code & the libraries from http://myarduinoprojects.com/modbus.html. Please suggest me corrections if necessary. Also is there another working example available for modbus tcp/ip on arduino.
#include <SPI.h>
#include <Ethernet.h>
#include "MgsModbus.h"
MgsModbus Mb;
int inByte = 0; // incoming serial byte
// Ethernet settings (depending on MAC and Local network)
byte mac[] = {0x00, 0x1A, 0xB6, 0x02, 0xD1, 0x14 };
IPAddress ip(192, 168, 0, 35);
void setup()
{
// serial setup
Serial.begin(9600);
Serial.println("Serial interface started");
// initialize the ethernet device
Ethernet.begin(mac, ip); // start etehrnet interface
Serial.println("Ethernet interface started");
// print your local IP address:
Serial.print("My IP address: ");
for (byte thisByte = 0; thisByte < 4; thisByte++) {
// print the value of each byte of the IP address:
Serial.print(Ethernet.localIP()[thisByte], DEC);
Serial.print(".");
}
Serial.println();
// slave address
Mb.remSlaveIP = (192,168,0,1);
// Fill MbData
// Mb.SetBit(0,false);
Mb.MbData[0] = 1;
Mb.MbData[1] = 2;
Mb.MbData[2] = 3;
Mb.MbData[3] = 4;
Mb.MbData[4] = 5;
Mb.MbData[5] = 6;
Mb.MbData[6] = 0;
Mb.MbData[7] = 0;
Mb.MbData[8] = 0;
Mb.MbData[9] = 0;
Mb.MbData[10] = 0;
Mb.MbData[11] = 0;
// print MbData
for (int i=0;i<12;i++) {
Serial.print("address: "); Serial.print(i); Serial.print("Data: "); Serial.println(Mb.MbData[i]);
}
// print menu
Serial.println("0 - print the first 12 words of the MbData space");
Serial.println("1 - FC 1 - read the first 5 coils from the slave and store them in the lower byte of MbData[1]");
Serial.println("2 - FC 2 - read the first 5 discrete inputs from the slave and store them in the higer of the MbData[1]");
Serial.println("3 - FC 3 - read the first 5 registers from the slave and store them in MbData[3..7");
Serial.println("4 - FC 4 - read the first 5 input registers from the slave and store them in MbData[8..12]");
Serial.println("5 - FC 5 - write coil 0 of the slave with the bit valeu of MbData[0.0]");
Serial.println("6 - FC 6 - write register 0 of the slave with MbData[2]");
Serial.println("7 - FC 15 - write 5 coils of the slave starting with coil 0 with GetBit(16..20");
Serial.println("8 - Fc 16 - write 5 registers of the slave starting on register 0 with MbData[0..4]");
Serial.println(Mb.remSlaveIP);
}
void loop()
{
if (Serial.available() > 0) {
// get incoming byte:
inByte = Serial.read();
if (inByte == '0') { // print MbData
for (int i=0;i<12;i++) {
Serial.print("address: "); Serial.print(i); Serial.print("Data: "); Serial.println(Mb.MbData[i]);
}
}
if (inByte == '1') {Mb.Req(MB_FC_READ_COILS, 6,6,6);} // 1 // ref, count, pos
if (inByte == '2') {Mb.Req(MB_FC_READ_DISCRETE_INPUT, 6,6,6);} // 2
if (inByte == '3') {Mb.Req(MB_FC_READ_REGISTERS, 6,6,6);} // 3
if (inByte == '4') {Mb.Req(MB_FC_READ_INPUT_REGISTER, 6,6,6);} // 4
if (inByte == '5') {Mb.Req(MB_FC_WRITE_COIL, 0,0,0);} // 5 // count can be x
if (inByte == '6') {Mb.Req(MB_FC_WRITE_REGISTER, 7,0,0);} // 6 // count can be x
if (inByte == '7') {Mb.Req(MB_FC_WRITE_MULTIPLE_COILS, 0,6,0);} // 15
if (inByte == '8') {Mb.Req(MB_FC_WRITE_MULTIPLE_REGISTERS, 0,6,0);} // 16
}
Mb.MbmRun();
// Mb.MbsRun();
}