title: python pymodbus read holding registers
body: <p>Im new to Modbus python and now i have some questions about my first steps</p>
  
  <p>The Script:  </p>
  
  <pre><code>from pymodbus.client.sync import ModbusTcpClient
  
  host = '10.8.3.10'
  port = 502   
  
  client = ModbusTcpClient(host, port)
  client.connect()
  
  #Register address 0x102A (4138dec) with a word count of 1
  #Value - MODBUS/TCP Connections
  #Access - Read
  #Description - Number of TCP connections
  
  request = client.read_holding_registers(0x3E8,10,unit=0) 
  response = client.execute(request)
  
  print response
  #print response.registers
  print response.getRegister(12)
  print response.registers[8]
  client.close()
  </code></pre>
  
  <p>The result:</p>
  
  <pre><code>============= RESTART: D:\Users\mxbruckn\Desktop\read_modbus.py =============
  ReadRegisterResponse (38)
  0
  0
  &gt;&gt;&gt; 
  </code></pre>
  
  <p>Now the questions: </p>
  
  <ol>
  <li><p>I read from Register 1000, 10 Words, with slave number 0. is this correct, but what means the value 38</p></li>
  <li><p>How can i read 2 Words from register 1007? my code does not work: (0x3EF,2, unit=0) Exception Response(131, 3, IllegalValue)</p></li>
  </ol>
  
  <p>Ciao,
  Doc</p>