Re: GPIB test on HP8510C electrical-optical calibration

[Stefan Mahr]

> From what I am debugging each complex pair is 50 bytes
> Using the Matlab script, it reads the whole 801 pairs, it is
> 40050 bytes
> There is a buch of spaces and LF characters.

> There is no option to read in steps..... once you tell the VNA to
> output data... it is going to blast the GPIB until everything
> is out.

> Yes, you are correct, changing the format would reduce the amount
> of data.

Some mails before you talk about 1M points. 801 sounds much more
reasonable to me. It should be no problem to transfer this at once. I'm
fairly sure I already tried such transfers, but if I have some time
tomorrow I will recheck.


> The gpib_read is only giving me 401, 20050 bytes which is half of it.

Is it 401 with every try? If so, did you check the initialization of
your HP8510C? According to manual 401 points is one of the five valid
settings.

Please also check the buffer size of the gpib_read call. It's no problem
to make it much larger than the data you expect.

Is your GPIB timeout correct. It's not given in seconds like with
MATLAB, it uses the linux-gpib timeout value instead:
http://linux-gpib.sourceforge.net/doc_html/r2137.html
(e.g. 9 = 100ms, 11 = 1s, 13 = 10s)


> The information in is the manual.... I have to find where we left the
> paper copy and do some RTFM.

Google says:
http://sigma.ucsd.edu/Facilities/manuals/8510C.pdf