Wind Speed and Wind Direction Sensor with RS485 Protocol

Greetings, recently I get a new project from my office to monitor some environment parameter such as wind speed and wind direction, they use QYCG 09 ultrasonic wind speed and wind direction sensor. link on aliexpress catalog: QYCG 09 Ultrasonic wind speed and direction sensor integrated environmental monitoring wind speed and direction instrument|Level Measuring Instruments| - AliExpress

At first, I think the data can be acquired with some example code from modbus master library in arduino, in my past projects it works 100% all the time, but it didn't work with this sensor. I get another issue because I can't find any datasheet or user manual of this sensor. Till now I still can't get any data from this sensor, here is the sample code that I often use:

void initRS485() {
  pinMode(MAX485_RE_NEG, OUTPUT);
  pinMode(MAX485_DE, OUTPUT);
  // Init in receive mode
  digitalWrite(MAX485_RE_NEG, 0);
  digitalWrite(MAX485_DE, 0);

  // Modbus slave ID 1
  node.begin(1, Serial1);
  // Callbacks allow us to configure the RS485 transceiver correctly
  node.preTransmission(preTransmission);
  node.postTransmission(postTransmission);
}

void readRS485() {
  resultMain = node.readHoldingRegisters(0x0000, 4);                  // Membaca register dari 0x0000,0x0001,0x0002 dan 0x0003 (ada 4 data)
  //resultMain = node.readHoldingRegisters(0x0000, 32);                  // Membaca register dari 0x0000,0x0001,0x0002 dan 0x0003 (ada 4 data)
  if (resultMain == node.ku8MBSuccess)
  {
    Serial.println(node.getResponseBuffer(0x01));                     // lihat data sheet (original report number)
  }
  delay (1000);
}

void preTransmission()
{
  digitalWrite(MAX485_RE_NEG, 1);
  digitalWrite(MAX485_DE, 1);
}

void postTransmission()
{
  digitalWrite(MAX485_RE_NEG, 0);
  digitalWrite(MAX485_DE, 0);
}

When I try to check the status of "node.ku8MBSuccess" it always return -1 and the value of "resultMain" always 256 no matter what registry that's been set.

Anyone have worked with this sensor before? Or do you have any advice for my issues?

Thanks before, greetings