title: How to access Agilent Devices using python and GPIB interface (with help of NI GPIB to USB converter)?
body: <p>I want to access <strong>Agilent Device N3301A</strong> using python. In purpose to connect to <a href="http://www.ni.com/gpib/" rel="nofollow">GPIB</a> port I am using a <a href="http://www.ni.com/gpib/" rel="nofollow">GPIB</a> to USB adapter from National Instruments. I have installed <a href="http://pyvisa.readthedocs.org/en/latest/" rel="nofollow">PyVisa</a>, Agilent Connection Expert as well.</p>
  
  <p>The code which I used in python is</p>
  
  <pre class="lang-py prettyprint-override"><code>import sys
  # create visa object
  import visa
  dcel = visa.instrument('GPIB::17::INSTR')
  print dcel.ask('*idn?')
  </code></pre>
  
  <p>This code does not works. Please, explain?</p>