I'm developing a Node.js application to communicate with a ZKTeco MA300 biometric device over TCP. I'm running a mock server to test the connection, but I'm facing an issue where the connection gets reset with an ECONNRESET error.

What I’ve Done:

1. Started a TCP server using Node.js with the net module, listening on port 4370.
2. The server successfully accepts connections and receives data from the device.
3. It sends a response with the MA300 device info when it detects a known request.

However, after a few messages, the connection gets disconnected with a "

Socket error: read ECONNRESET

" message.

const net = require('net');

const PORT = 4370;
const HOST = '0.0.0.0';

// MA300 Device Info Response
const DEVICE_INFO_RESPONSE = Buffer.from(
  'aa01760000004d4133303051544d363234313030303031c0a8003233333265333532653333bc97',
  'hex'
);

const server = net.createServer((socket) => {
  console.log(`ZK Software connected: ${socket.remoteAddress}:${socket.remotePort}`);

  socket.on('data', (data) => {
    console.log(`Received: ${data.toString('hex')}`);

    if (data.toString('hex').startsWith('aa01760400fefefefe')) {
      console.log('Sending MA300 Device Info...');
      socket.write(DEVICE_INFO_RESPONSE);
    } else {
      console.warn('Unknown request received');
    }
  });

  socket.on('error', (err) => {
    console.error(`Socket error: ${err.message}`);
  });

  socket.on('close', () => {
    console.log('ZK Software disconnected');
  });
});

server.listen(PORT, HOST, () => {
  console.log(`Mock ZK MA300 Server running on ${HOST}:${PORT}`);
});

Questions:

1. What could be causing the ECONNRESET error after a few responses?
2. Does the MA300 require an additional handshake or acknowledgment after sending the device info?
3. Are there specific ZKTeco protocol requirements that I might be missing?