Data acquisition

[Nick Dokos]

spintronic <sidorenko.andrey at gmail.com> wrote:

> Dear friends,
> 
> I have a trouble with understanding the following. I have a very short
> script (shown below) which works fine if I "run" step by step (or line
> by line) in Python shell (type the first line/command -> press Enter,
> etc.). I can get all numbers (actually, there are no numbers but a
> long string, but this is not a problem) I need from a device:
> 
> '0.3345098119,0.01069121274,0.02111624694,0.03833379529,0.02462816409,0.0774275008,0.06554297421,0.07366750919,0.08122602002,0.004018369318,0.03508462415,0.04829900696,0.06383554085, ...'
> 
> However, when I start very the same list of commands as a script, it
> gives me the following, which is certainly wrong:
> 
> [0.0, 0.0, 0.0, 0.0, 0.0,...]
> 
> Any ideas? Why there is a difference when I run the script or do it
> command by command?
> 
> ===========================
> from visa import *
> 
> mw = instrument("GPIB0::20::INSTR", timeout = None)
> 
> mw.write("*RST")
> mw.write("CALC1:DATA? FDATA")
> 
> a=mw.read()
> 
> print a
> ===========================
> (That is really all!)
> 
> 
> PS In this case I use Python Enthought for Windows, but I am not an
> expert in Windows (I work usually in Linux but now I need to run this
> data acquisition under Windows).
> -- 
> http://mail.python.org/mailman/listinfo/python-list
> 

Shot in the dark: could it be that you have to add delays to give the
instrument time to adjust? When you do it from the python shell, line by
line, there is a long delay between one line and the next.

Nick