Help- to get meter data by android app

I'm trying to build app for get meter serial number using Android DLMS package. not able to get data from the meter.

My code is:
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.util.Log;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import gurux.common.ReceiveParameters;
import gurux.common.enums.TraceLevel;
import gurux.common.GXCommon;
import gurux.dlms.GXDLMSClient;
import gurux.dlms.GXReplyData;
import gurux.dlms.enums.Authentication;
import gurux.dlms.enums.InterfaceType;
import gurux.dlms.objects.GXDLMSData;
import gurux.io.BaudRate;
import gurux.io.Parity;
import gurux.io.StopBits;
import gurux.serial.GXPort;
import gurux.serial.GXSerial;

public class MainActivity extends AppCompatActivity {

private static final String TAG = "MeterReader";
private TextView tvMeterValue;
private TextView tvStatus;
private Button btnRead;
private GXSerial media;
private GXDLMSClient client;
private final Handler uiHandler = new Handler(Looper.getMainLooper());
private final ExecutorService executor = Executors.newSingleThreadExecutor();
private final Object serialLock = new Object();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvMeterValue = findViewById(R.id.tvMeterValue);
tvStatus = findViewById(R.id.tvStatus);
btnRead = findViewById(R.id.btnRead);

client = new GXDLMSClient(
true,
32,
1,
Authentication.LOW,
"lnt1",
InterfaceType.HDLC
);
media = new GXSerial(this);
media.setTrace(TraceLevel.VERBOSE);
btnRead.setOnClickListener(v -> startRead());
}

private void startRead() {
btnRead.setEnabled(false);
tvMeterValue.setText("---");
logStatus("Scanning for ports...");
executor.execute(() -> {
try {
synchronized (serialLock) {
if (!media.isOpen()) {
GXPort[] ports = media.getPorts();
if (ports == null || ports.length == 0) {
throw new Exception("No optical probe detected. Please reconnect it.");
}
media.setPort(ports[0]);
media.setBaudRate(BaudRate.BAUD_RATE_9600);
media.setDataBits(8);
media.setParity(Parity.NONE);
media.setStopBits(StopBits.ONE);
logStatus("Opening: " + ports[0].getPort());
media.open();
try {
media.setRtsEnable(true);
media.setDtrEnable(true);
} catch (Exception e) {
Log.w(TAG, "Failed to set control lines", e);
}
Thread.sleep(1000);
}
logStatus("Connecting to meter...");
initializeConnection();
logStatus("Reading Serial Number...");
GXDLMSData snObj = new GXDLMSData("0.0.96.1.0.255");
GXReplyData reply = new GXReplyData();
// Read attribute 2 (Value)
readDLMS(client.read(snObj, 2), reply);
final String serialNum = String.valueOf(reply.getValue());
uiHandler.post(() -> {
tvMeterValue.setText(serialNum);
btnRead.setEnabled(true);
Toast.makeText(this, "Read Successful!", Toast.LENGTH_SHORT).show();
});
logStatus("Success");
}
} catch (Exception e) {
logStatus("Error: " + e.getMessage());
Log.e(TAG, "Communication error", e);
uiHandler.post(() -> btnRead.setEnabled(true));
try {
synchronized (serialLock) {
media.close();
}
} catch (Exception ignored) {
}
}
});
}

private void initializeConnection() throws Exception {

GXReplyData reply = new GXReplyData();
// 1. SNRM
logStatus("Sending SNRM...");
readDLMS(client.snrmRequest(), reply);
// 2. AARQ
logStatus("Sending AARQ...");
readDLMS(client.aarqRequest(), reply);
}

private void readDLMS(byte[] data, GXReplyData reply) throws Exception {
readDLMS(new byte[][]{data}, reply);
}

private void readDLMS(byte[][] data, GXReplyData reply) throws Exception {
if (data == null) return;
for (byte[] frame : data) {
if (frame == null || frame.length == 0) continue;
media.resetSynchronousBuffer();
Log.d(TAG, "TX: " + GXCommon.bytesToHex(frame));
media.send(frame);
reply.clear();
long startTime = System.currentTimeMillis();
while (!reply.isComplete()) {
if (System.currentTimeMillis() - startTime > 10000) {
throw new Exception("Meter response timeout");
}
ReceiveParameters<byte[]> rp = new ReceiveParameters<>(byte[].class);
rp.setWaitTime(5000);
rp.setEop((byte) 0x7E); // HDLC frame end character
rp.setCount(1); // Wait for at least 1 byte
if (media.receive(rp)) {
byte[] response = rp.getReply();
if (response != null && response.length > 0) {
Log.d(TAG, "RX: " + GXCommon.bytesToHex(response));
client.getData(response, reply);
}
}
}
if (reply.getError() != 0) {
throw new Exception("DLMS Error Code: " + reply.getError());
}
}
}
private void logStatus(String msg) {
uiHandler.post(() -> tvStatus.setText(msg));
Log.d(TAG, msg);
}

@Override
protected void onDestroy() {
super.onDestroy();
executor.shutdownNow();
if (media != null) {
try {
synchronized (serialLock) {
media.close();
}
} catch (Exception ignored) {
}
}
}
}