ADS1299: Data Ready pin not going low.

Sir, 

I have been experimenting with ADS1299 for few days. Yesterday I made a program to extract raw data (random noise) available on 1nxP and 1nxN pins. I was able to get some values on Arduino Serial Monitor. I am using ESP32 as a controller. Today I started with the setup, with the same connections of SPI + DRDY + RESET. But now the data ready pin remains HIGH all the time. By making the corresponding input of ESP32 wrt DRDY pin LOW, I am able to extract some random data. The power supplies and code remains the same as yesterday. The program has sent the RDATAC command to gather data. 
I wanted to know how did this problem emerge! Is there any condition on DRDY to go low. Yesterday the same program was working fine with no flaws. Below is the function I have used in Void Main() of Arduino IDE for ESP32. 

void getADSdata(){
  long dataPacket = 0;
  vspi->beginTransaction(SPISettings(spiClk, MSBFIRST, SPI_MODE1));
  digitalWrite(ADS_CS, LOW); //Low to communicated  

  for(int i = 0; i<3; i++){
     byte dataByte = vspi->transfer(0x00);
     statusData = (dataPacket<<8) | dataByte;
  }
  for(int i = 0; i<8; i++){
    for(int j = 0; j<3; j++){
        byte dataByte = vspi->transfer(0x00);
        dataPacket = (dataPacket<<8) | dataByte;
    }
    output[i] = dataPacket;
    dataPacket = 0;
  }

  digitalWrite(ADS_CS, HIGH);
  vspi->endTransaction();

  
  #ifdef DEBUG
    for (int i=0;i<8; i++) {
        Serial.print("Data[" + String(i) + "]: ");
        Serial.print(output[i], HEX);
        if(i!=8) Serial.print(", ");
        
    }
    Serial.println();
  #endif
}