QModBus Invalid CRC

[proasnet]

Hi, I am trying found a ideal RTU modbus library. Now, I am trying an example, on Arduino Mega 2560 ( Later on ESP32 ). As a master is a PC with QModBus. Between PC and Ardino is a converter with Tx En. On any ask from a PC, I get some data, but always with CRC Error.

#include <ModbusRTUSlave.h>

const byte buttonPins[2] = {2, 3};
const byte ledPins[4] = {5, 6, 7, 8};

//HardwareSerial RS485(1);
ModbusRTUSlave modbus( Serial1 , 13 ); // serial port, driver enable pin for rs-485

bool coils[2];
bool discreteInputs[2];
uint16_t holdingRegisters[2];
uint16_t inputRegisters[2];

void setup() {

  Serial1.begin( 9600 );

  pinMode(buttonPins[0], INPUT_PULLUP);
  pinMode(buttonPins[1], INPUT_PULLUP);
  pinMode(ledPins[0], OUTPUT);
  pinMode(ledPins[1], OUTPUT);
  pinMode(ledPins[2], OUTPUT);
  pinMode(ledPins[3], OUTPUT);

  modbus.configureCoils(coils, 2);                       // bool array of coil values, number of coils
  modbus.configureDiscreteInputs(discreteInputs, 2);     // bool array of discrete input values, number of discrete inputs
  modbus.configureHoldingRegisters(holdingRegisters, 2); // unsigned 16 bit integer array of holding register values, number of holding registers
  modbus.configureInputRegisters(inputRegisters, 2);     // unsigned 16 bit integer array of input register values, number of input registers

  modbus.begin( 1 , 9600);
}

void loop() {
  inputRegisters[0] = 500;
  inputRegisters[1] = 550;
  discreteInputs[0] = !digitalRead(buttonPins[0]);
  discreteInputs[1] = !digitalRead(buttonPins[1]);

  modbus.poll();

  analogWrite(ledPins[0], holdingRegisters[0]);
  analogWrite(ledPins[1], holdingRegisters[1]);
  digitalWrite(ledPins[2], coils[0]);
  digitalWrite(ledPins[3], coils[1]);
}

[CMB27]

It looks like something is going wrong with the data being received or how it is being received by your computer.

It looks like you are sending the following request. 01 - Slave/Server ID 01 - Function Code 1 (Read Coils) 00 00 - Starting Data/Coil Address 00 01 - Number of Coils to Read FD CA - CRC Code (I'm pretty sure this is what QModBus is sending, otherwise you probably wouldn't get a response.)

The appropriate response is the following. 01 - Slave/Server ID 01 - Function Code 1 (Read Coils) 01 - Coil Data Byte Count 00 - Coil Data 51 88 - CRC Code

If you look at the raw data you are receiving, you are getting this message, there is just other data around it.

[proasnet]

In a few days I will test again, the new HW revision will be ready, so I will send the data from the modbus test