Modbus write single register code. Not working, can someone tell me why ?

[Nestor973]

#include <Controllino.h>

#include “ModbusRtu.h”

#define MasterModbusAdd 0

#define SlaveModbusAdd 1

#define RS485Serial 3

int i;

unsigned long u32wait;

uint16_t au16data[16];

uint8_t u8state;

char caracter;

String ch;

int value;

Modbus master(MasterModbusAdd, RS485Serial, 0);

modbus_t data[1];

uint16_t ModbusSlaveRegisters[4];

void setup() {

Serial.begin(115200);

while (!Serial){

}

Serial.println(“Connecting to Serial3 “);

master.begin(19200,SERIAL_8E1);

Serial.println(“Connected”);

Serial.println(“Enter desiderd address :”);

master.setTimeOut(5000); // if there is no answer in 5000 ms, roll over

u32wait = millis() + 2000;

u8state = 0;

i=0;

ch=””;

data[0].u8id = SlaveModbusAdd; // slave address

data[0].u8fct = 6; // function code (this one is registers read)

data[0].u16RegAdd = 19; // start address in slave

data[0].u16CoilsNo = 1; // number of elements (coils or registers) to read

data[0].au16reg = 123 ; //ModbusSlaveRegisters+4; // pointer to a memory array in the Arduino

//ModbusSlaveRegisters[4] = 123;

}

void loop() {

while (Serial.available()){

caracter = Serial.read();

ch.concat(caracter);

}

if (ch.toInt()>=1 and ch.toInt()<=247)

{

Serial.print(“Number received: “);

Serial.println(ch);

value = ch.toInt();

ch=””;

}

else

{

//Serial.print(“bad number”);

//Serial.println(ch);

}

delay(50);

switch( u8state ) {

case 0:

if (millis() > u32wait) u8state++; // wait state

break;

case 1:

if (value>=1 and value<=247)

master.query(data[0]); // send query (only once)

u8state++;

break;

case 2:

master.poll(); // check incoming messages

if (master.getState() == COM_IDLE) {

//u8state = 0;

u32wait = millis() + 500;

Serial.println (“Value written : “);

u8state++;

}

break;

}

} //

[Lukas]

Hi,

Do you have problem with register read (like in your sketch) or with register write (like in the title of the issue)?

Do you have any progress so far?

Thanks,

Lukas