diff --git a/NewLife.Siemens/Protocols/S7PLC.cs b/NewLife.Siemens/Protocols/S7PLC.cs
index be0b39f..4850c67 100644
--- a/NewLife.Siemens/Protocols/S7PLC.cs
+++ b/NewLife.Siemens/Protocols/S7PLC.cs
@@ -254,11 +254,11 @@ private async Task<COTP> RequestAsync(Stream stream, COTP request, CancellationT
         try
         {
             var pk = request.GetBytes(true);
-            var buf = pk.ReadBytes();
+            //var buf = pk.ReadBytes();
 
             using var closeOnCancellation = cancellationToken.Register(Close);
-            //await pk.CopyToAsync(stream, cancellationToken);
-            await stream.WriteAsync(buf, 0, buf.Length, cancellationToken);
+            await pk.CopyToAsync(stream, cancellationToken);
+            //await stream.WriteAsync(buf, 0, buf.Length, cancellationToken);
             return await COTP.ReadAsync(stream, cancellationToken).ConfigureAwait(false);
         }
         catch (Exception exc)
diff --git a/NewLife.Siemens/Protocols/S7Server.cs b/NewLife.Siemens/Protocols/S7Server.cs
index 6bfdc51..9df0052 100644
--- a/NewLife.Siemens/Protocols/S7Server.cs
+++ b/NewLife.Siemens/Protocols/S7Server.cs
@@ -10,6 +10,8 @@ public S7Server()
     {
         Port = 102;
         ProtocolType = NetType.Tcp;
+
+        Add(new TPKTCodec());
     }
 }
 
diff --git a/NewLife.Siemens/Protocols/TPKT.cs b/NewLife.Siemens/Protocols/TPKT.cs
index 6c114b0..d0783f7 100644
--- a/NewLife.Siemens/Protocols/TPKT.cs
+++ b/NewLife.Siemens/Protocols/TPKT.cs
@@ -12,6 +12,7 @@ namespace NewLife.Siemens.Protocols;
 /// </remarks>
 public class TPKT
 {
+    #region 属性
     /// <summary>版本</summary>
     public Byte Version { get; set; }
 
@@ -23,21 +24,11 @@ public class TPKT
 
     /// <summary>数据</summary>
     public Packet Data { get; set; }
-
-    /// <summary>实例化</summary>
-    public TPKT() { }
-
-    private TPKT(Byte version, Byte reserved1, Int32 length, Byte[] data)
-    {
-        Version = version;
-        Reserved = reserved1;
-        Length = (UInt16)length;
-        Data = data;
-    }
+    #endregion
 
     /// <summary>解析数据</summary>
     /// <param name="pk"></param>
-    public void Read(Packet pk)
+    public TPKT Read(Packet pk)
     {
         var buf = pk.ReadBytes(0, 4);
         Version = buf[0];
@@ -45,6 +36,8 @@ public void Read(Packet pk)
         Length = buf.ToUInt16(2, false);
 
         if (pk.Total > 4) Data = pk.Slice(4, Length);
+
+        return this;
     }
 
     /// <summary>解析数据</summary>
@@ -87,6 +80,15 @@ public Byte[] ToArray()
         return ms.ToArray();
     }
 
+    /// <summary>获取字节数组</summary>
+    /// <returns></returns>
+    public Packet ToPacket()
+    {
+        var ms = new MemoryStream();
+        Write(ms);
+        return new Packet(ms);
+    }
+
     /// <summary>
     /// Reads a TPKT from the socket Async
     /// </summary>
diff --git a/NewLife.Siemens/Protocols/TPKTCodec.cs b/NewLife.Siemens/Protocols/TPKTCodec.cs
new file mode 100644
index 0000000..f31fe57
--- /dev/null
+++ b/NewLife.Siemens/Protocols/TPKTCodec.cs
@@ -0,0 +1,64 @@
+using NewLife.Data;
+using NewLife.Messaging;
+using NewLife.Model;
+using NewLife.Net.Handlers;
+
+namespace NewLife.Siemens.Protocols;
+
+/// <summary>编码器</summary>
+public class TPKTCodec : MessageCodec<TPKT>
+{
+    /// <summary>实例化编码器</summary>
+    public TPKTCodec() => UserPacket = false;
+
+    /// <summary>编码</summary>
+    /// <param name="context"></param>
+    /// <param name="msg"></param>
+    /// <returns></returns>
+    protected override Object Encode(IHandlerContext context, TPKT msg)
+    {
+        if (msg is TPKT cmd) return cmd.ToPacket();
+
+        return null;
+    }
+
+    /// <summary>解码</summary>
+    /// <param name="context"></param>
+    /// <param name="pk"></param>
+    /// <returns></returns>
+    protected override IList<TPKT> Decode(IHandlerContext context, Packet pk)
+    {
+        var ss = context.Owner as IExtend;
+        if (ss["Codec"] is not PacketCodec pc)
+            ss["Codec"] = pc = new PacketCodec { GetLength = p => GetLength(p, 3, 1) - 4, Offset = 3 };
+
+        var pks = pc.Parse(pk);
+        var list = pks.Select(e => new TPKT().Read(e)).ToList();
+
+        return list;
+    }
+
+    /// <summary>连接关闭时，清空粘包编码器</summary>
+    /// <param name="context"></param>
+    /// <param name="reason"></param>
+    /// <returns></returns>
+    public override Boolean Close(IHandlerContext context, String reason)
+    {
+        if (context.Owner is IExtend ss) ss["Codec"] = null;
+
+        return base.Close(context, reason);
+    }
+
+    /// <summary>是否匹配响应</summary>
+    /// <param name="request"></param>
+    /// <param name="response"></param>
+    /// <returns></returns>
+    protected override Boolean IsMatch(Object request, Object response)
+    {
+        if (request is not TPKT req || response is not TPKT res) return false;
+
+        // 不支持链路复用，任意响应都是匹配的
+
+        return true;
+    }
+}
\ No newline at end of file