title: Python VISA serial polling function
body: <p>I have an issue with one of my <strong>GPIB</strong> instruments. It is quite an old one, and it is stated as IEEE-488-1978. I have been trying to get the reference manual for that version of IEEE-488, but it has not been successful.</p>
  
  <p>The issue regards the fact that in order to read the Status Register of the instrument it requires a <strong>Serial Polling Function</strong> (as its reference manual says). I do not know how can I do so in Python using <strong>PyVISA</strong>.</p>
  
  <p>For example, what I am using to read from the device is <code>_instrument.ask("RV")_</code>, where <code>_RV_</code> means <code>_Read Version_</code>. Also, for writing a parameter like temperature, I do <code>_instrument.write("ST20.00")_</code>, where <code>_ST20.00_</code> means <code>_Set Temperature to 20.00 Celcius_</code>.</p>
  
  <p>I have been trying to find an ASCII command to send to the instrument with the <code>_ask_</code> Python/VISA command and get in return the <code>_Status Register Byte_</code>, but there seems to be nothing feasible.</p>
  
  <p>If anybody has a suggestion, regarding how to pass a serial polling function with Python/VISA, that could solve my issue.</p>