Merge branch 'master' of https://github.com/ljean/modbus-tk

README.md

@@ -35,6 +35,7 @@ Features
 ------------------------------------
 * Modbus TCP support for writing masters and slaves
 * Modbus RTU support for writing masters and slaves (requires pyserial)
+* Modbus RTU over TCP support
 * Can be customized with hook mechanism (simulate errors, timeouts...)
 * ready-to use simulator with RPC interface
 * Defines very easily your own memory blocks

modbus_tk/__init__.py

@@ -29,6 +29,7 @@
 * Vincent Prince
 * kcl93
 * https://github.com/Slasktra
+* travijuu
 
 Please let us know if your name is missing!
 

modbus_tk/hooks.py

@@ -49,6 +49,8 @@ def install_hook(name, fct):
     modbus_tcp.TcpServer.before_send((server, sock, response)) returns modified response or None
     modbus_tcp.TcpServer.on_error((server, sock, excpt))
 
+    modbus_rtu_over_tcp.RtuOverTcpMaster.after_recv((master, response))
+
     modbus.Master.before_send((master, request)) returns modified request or None
     modbus.Master.after_send((master))
     modbus.Master.after_recv((master, response)) returns modified response or None

modbus_tk/modbus_rtu_over_tcp.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+ Modbus TestKit: Implementation of Modbus protocol in python
+
+ (C)2009 - Luc Jean - luc.jean@gmail.com
+ (C)2009 - Apidev - http://www.apidev.fr
+
+ This is distributed under GNU LGPL license, see license.txt
+"""
+
+from modbus_tk.hooks import call_hooks
+from modbus_tk.modbus_rtu import RtuQuery
+from modbus_tk.modbus_tcp import TcpMaster
+from modbus_tk.utils import to_data
+
+
+class RtuOverTcpMaster(TcpMaster):
+    """Subclass of TcpMaster. Implements the Modbus RTU over TCP MAC layer"""
+
+    def _recv(self, expected_length=-1):
+        """Receive the response from the slave"""
+        response = to_data('')
+        length = 255
+        while len(response) < length:
+            rcv_byte = self._sock.recv(1)
+            if rcv_byte:
+                response += rcv_byte
+            if expected_length >= 0 and len(response) >= expected_length:
+                break
+        retval = call_hooks("modbus_rtu_over_tcp.RtuOverTcpMaster.after_recv", (self, response))
+        if retval is not None:
+            return retval
+        return response
+
+    def _make_query(self):
+        """Returns an instance of a Query subclass implementing the modbus RTU protocol"""
+        return RtuQuery()