Aw: Re: GPIB serial poll of an instrument

[Stefan Mahr]

> That is a common misconception, 
> For complex microwave setups, while the instrument is busy it will not 
> respond to the command (specially old HP equipment)
> So if you have another instrument that finished a particular task requesting 
> service (but you are unable to know this), basically the system will hang and 
> you could lose data.
> The beauty of serial poll for complex setups is that you can just check with 
> a single instruction whether something is done or not
> without having to go around instrument by instrument using their particular 
> instruction for checking the status byte and risking hanging
> due to a timeout. Remember, you do not know how long it would take.... you 
> could get a bad sample an it would be done in a few seconds
> or a good one and it will take some time depending what you need to measure.
> 
> I am talking about old HP equipment... most newer Agilent uses SCPI... but 
> still not all manufacturers use the SCPI format.
> 
> This is coming from the old HP engineers who work on the original HPIB.... we 
> have a few around.
> 
> Matlab has the spoll function.. which is nice.
> 
> So it is not so trivial...

I added a simple spoll to instrument-control. Please download the test version 
from:
https://github.com/dac922/octave-instrument-control/archive/port2forge.tar.gz

and install from octave with:
pkg install /path/to/port2forge.tar.gz

--

a=gpib(20,11);
gpib_spoll(a)   % returns true if RQS bit is set and false if RQS is clear.



Stefan