3 files changed, 29 insertions, 15 deletions
diff --git a/src/org/traccar/protocol/At2000FrameDecoder.java b/src/org/traccar/protocol/At2000FrameDecoder.java
index d0be3f5f4..4c849afb7 100644
--- a/src/org/traccar/protocol/At2000FrameDecoder.java
+++ b/src/org/traccar/protocol/At2000FrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2017 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,16 +16,31 @@
 package org.traccar.protocol;
 
 import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
 import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 import org.jboss.netty.handler.codec.frame.FrameDecoder;
 
+import java.nio.ByteOrder;
+
 public class At2000FrameDecoder extends FrameDecoder {
 
     private static final int BLOCK_LENGTH = 16;
+    private static final int ACK_LENGTH = 496;
 
     private boolean firstPacket = true;
 
+    private void sendResponse(Channel channel) {
+        if (channel != null) {
+            ChannelBuffer response = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, 2 * BLOCK_LENGTH);
+            response.writeByte(At2000ProtocolDecoder.MSG_ACKNOWLEDGEMENT);
+            response.writeMedium(ChannelBuffers.swapMedium(1));
+            response.writeByte(0x00); // success
+            response.writerIndex(2 * BLOCK_LENGTH);
+            channel.write(response);
+        }
+    }
+
     @Override
     protected Object decode(
             ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
@@ -47,6 +62,10 @@ public class At2000FrameDecoder extends FrameDecoder {
             length = (length / BLOCK_LENGTH + 1) * BLOCK_LENGTH;
         }
 
+        if (buf.readableBytes() >= length || buf.readableBytes() % ACK_LENGTH == 0) {
+            sendResponse(channel);
+        }
+
         if (buf.readableBytes() >= length) {
             return buf.readBytes(length);
         }
diff --git a/src/org/traccar/protocol/At2000ProtocolDecoder.java b/src/org/traccar/protocol/At2000ProtocolDecoder.java
index 989e0d136..58b6f44e8 100644
--- a/src/org/traccar/protocol/At2000ProtocolDecoder.java
+++ b/src/org/traccar/protocol/At2000ProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2017 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -48,17 +48,6 @@ public class At2000ProtocolDecoder extends BaseProtocolDecoder {
 
     private Cipher cipher;
 
-    private static void sendResponse(Channel channel) {
-        if (channel != null) {
-            ChannelBuffer response = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, 2 * BLOCK_LENGTH);
-            response.writeByte(MSG_ACKNOWLEDGEMENT);
-            response.writeMedium(ChannelBuffers.swapMedium(1));
-            response.writeByte(0x00); // success
-            response.writerIndex(2 * BLOCK_LENGTH);
-            channel.write(response);
-        }
-    }
-
     private static void sendRequest(Channel channel) {
         if (channel != null) {
             ChannelBuffer response = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, BLOCK_LENGTH);
@@ -136,8 +125,6 @@ public class At2000ProtocolDecoder extends BaseProtocolDecoder {
 
         }
 
-        sendResponse(channel);
-
         if (type == MSG_DEVICE_ID) {
             sendRequest(channel);
         }
diff --git a/test/org/traccar/protocol/At2000ProtocolDecoderTest.java b/test/org/traccar/protocol/At2000ProtocolDecoderTest.java
index 6df44eaed..60485c805 100644
--- a/test/org/traccar/protocol/At2000ProtocolDecoderTest.java
+++ b/test/org/traccar/protocol/At2000ProtocolDecoderTest.java
@@ -19,6 +19,14 @@ public class At2000ProtocolDecoderTest extends ProtocolTest {
         decoder = new At2000ProtocolDecoder(new At2000Protocol());
 
         verifyNothing(decoder, binary(ByteOrder.LITTLE_ENDIAN,
+                "01012f000000000000000000000000000033353734353430373136303631393637f5441a9862260117858237fe3160388490f0df7d46c09112ee087235a92101"));
+
+        verifyPosition(decoder, binary(ByteOrder.LITTLE_ENDIAN,
+                "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"));
+
+        decoder = new At2000ProtocolDecoder(new At2000Protocol());
+
+        verifyNothing(decoder, binary(ByteOrder.LITTLE_ENDIAN,
                 "01012f0000000000000000000000000000333537343534303731363035353033dd529a1eb5df9f3b6d320b38250e03306692957e8c2127d8e381a717f639b4c9"));
 
         verifyPosition(decoder, binary(ByteOrder.LITTLE_ENDIAN,