Added the ability to send RTU commands via TCP Serial Gateway

Author: Kelley Reynolds

AUTHORS

@@ -1,2 +1,3 @@
 Timin Aleksey
 James Sanders
+Kelley Reynolds

ChangeLog

@@ -57,4 +57,6 @@
 2010-02-6 Timin Aleksey <[email protected]>
 	* lib/rmodbus/client.rb, lib/rmodbus/tcp_client.rb:	Client#connection_retries don't use more 
 2010-07-16 Timin Aleksey <[email protected]>
-    * lib/rmodbus/rtu_client.rb: Added option read_timeout and accessor RTUClient#read_timeout
+	* lib/rmodbus/rtu_client.rb: Added option read_timeout and accessor RTUClient#read_timeout
+2010-07-28 Kelley Reynolds <[email protected]>
+	* lib/rmodbus/rtu_via_tcp_client.rb: Added the ability to send RTU commands via TCP Serial Gateway

lib/rmodbus.rb

@@ -13,4 +13,5 @@
 require 'rmodbus/tcp_server'
 require 'rmodbus/rtu_client'
 require 'rmodbus/rtu_server'
+require 'rmodbus/rtu_via_tcp_client'
 

lib/rmodbus/rtu_via_tcp_client.rb

@@ -0,0 +1,104 @@
+# RModBus - free implementation of ModBus protocol in Ruby.
+#
+# Copyright (C) 2009  Timin Aleksey
+# Copyright (C) 2010  Kelley Reynolds
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+require 'rmodbus/crc16'
+require 'timeout'
+require 'rmodbus/client'
+require 'rmodbus/exceptions'
+
+module ModBus
+  
+  class RTUViaTCPClient < Client
+
+    include CRC16
+    attr_reader :ipaddr, :port, :slave
+    attr_accessor :debug
+
+    # Connect with Serial TCP Gateway (eg barionet-50)
+    #
+    # ipaddr - ip of the server
+    #
+    # port - port TCP connections
+    #
+    # slaveaddr - slave ID of the server
+    #
+    # RTUViaTCPClient.connect('127.0.0.1') do |cl|
+    #
+    #   put cl.read_holding_registers(0, 10)
+    #
+    # end
+    def self.connect(ipaddr, port = 10002, slaveaddr = 1)
+      cl = RTUViaTCPClient.new(ipaddr, port, slaveaddr) 
+      yield cl
+      cl.close
+    end
+
+    # Connect with a ModBus server
+    #
+    # ipaddr - ip of the server
+    #
+    # port - port TCP connections
+    #
+    # slaveaddr - slave ID of the server
+    def initialize(ipaddr, port = 10002, slaveaddr = 1)
+      @ipaddr, @port = ipaddr, port
+      tried = 0
+      begin
+        timeout(1, ModBusTimeout) do
+          @sock = TCPSocket.new(@ipaddr, @port)
+        end
+      rescue ModBusTimeout => err
+        raise ModBusTimeout.new, 'Timed out attempting to create connection'
+      end
+      @slave = slaveaddr
+      @debug = false
+      super()
+    end
+
+    # Close TCP connections
+    def close
+      @sock.close unless @sock.closed?
+    end
+
+    # Check TCP connections
+    def closed?
+      @sock.closed?
+    end
+
+    protected
+    def send_pdu(pdu)
+      msg = @slave.chr + pdu 
+      msg << crc16(msg).to_word
+      @sock.write msg
+
+      log "Tx (#{msg.size} bytes): " + logging_bytes(msg) + "\n"
+    end
+
+    def read_pdu
+      msg = @sock.read(7)
+
+      log "Rx (#{msg.size} bytes): " + logging_bytes(msg) + "\n"
+
+      if msg.getbyte(0) == @slave
+        return msg[1..-3] if msg[-2,2].unpack('n')[0] == crc16(msg[0..-3])
+        log "Ignore package: don't match CRC\n"
+	  else 
+        log "Ignore package: don't match slave ID\n"
+      end
+      loop do
+        #waite timeout  
+      end
+    end
+  end
+end

rmodbus.gemspec

@@ -2,7 +2,7 @@ require 'rubygems'
 spec = Gem::Specification.new do |s|
   s.name = "rmodbus"
   s.version = "0.4.0"
-  s.author  = 'A.Timin, J. Sanders'
+  s.author  = 'A.Timin, J. Sanders, K. Reynolds'
   s.email = "[email protected]"
   s.homepage = "http://rmodbus.heroku.com"
   s.rubyforge_project = "RModBus"