Adruino Read Selec MF383A

 

Adruino read Selec MF383A via RS485 Modbus RTU

#include <ModbusRtu.h>
#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

uint16_t au16data[16];
uint8_t u8state;
unsigned long time1 = 0;
Modbus master(0,mySerial,0);
modbus_t telegram;

unsigned long u32wait;

void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);
  mySerial.begin(9600);
  master.start();
  master.setTimeOut( 2000 );
  u32wait = millis() + 1000;
  u8state = 0; 
}

void loop() {
  switch( u8state ) {
  case 0: 
    if (millis() > u32wait) u8state++; // wait state
    break;
  case 1: 
    telegram.u8id = 1; // slave address
    telegram.u8fct = 4; // function code (this one is registers read)
    telegram.u16RegAdd = 0; // start address in slave
    telegram.u16CoilsNo = 10; // number of elements (coils or registers) to read
    telegram.au16reg = au16data; // pointer to a memory array in the Arduino

    master.query( telegram ); // send query (only once)
    u8state++;
    break;
  case 2:
    master.poll(); // check incoming messages
    if (master.getState() == COM_IDLE) {
      u8state = 0;
      u32wait = millis() + 100; 
    }
    break;
  }

  if ( (unsigned long) (millis() - time1) > 1000 )
    {
      Serial.print("V1N: ");
      Serial.println(convertFloat(au16data[0], au16data[1]));
      Serial.print("V2N: ");
      Serial.println(convertFloat(au16data[2], au16data[3]));
      Serial.print("V3N: ");
      Serial.println(convertFloat(au16data[4], au16data[5]));
      Serial.print("Average Voltage LN: ");
      Serial.println(convertFloat(au16data[6], au16data[7]));
      
      time1 = millis();
    }

}

float convertFloat(uint16_t reg_low, uint16_t reg_high) {
  uint16_t data[2] = {reg_low, reg_high};
  float value;
  memcpy(&value, data, 4);
  return value;
}