[Octave-bug-tracker] [bug #58252] Instrument-control ustmc_read() does not read all the waveform data from oscilloscope

[anonymous]

URL:
  <https://savannah.gnu.org/bugs/?58252>

                 Summary: Instrument-control ustmc_read() does not read all
the waveform data from oscilloscope
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Sun 26 Apr 2020 11:44:27 PM UTC
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: Walter Sjursen
        Originator Email: address@hidden
             Open/Closed: Open
                 Release: 4.2.2
         Discussion Lock: Any
        Operating System: GNU/Linux

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Details:

This appears to be an instrument-control problem.

Computer and OS 
$uname -a
Linux Dell-XPS-15-9560 5.3.0-46-generic #38~18.04.1-Ubuntu SMP Tue Mar 31
04:17:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Octave version 4.2.2
Packages:
Package Name        | Version | Installation directory
--------------------+---------+-----------------------
           control *|   3.2.0 | /home/.../octave/control-3.2.0
instrument-control *|   0.5.0 | /home/.../octave/instrument-control-0.5.

I am connecting to a Keysight model DSO-X 1102G oscilloscope through a USB
connection as a usbtmc class device (/dev/usbtmc0).
When trying to read waveform data, only part of the waveform data is read. I
am using:
[data, nRead] = usbtmc_write(device,nChar)
It appears if nChar is larger than the "10 + number of samples" the function
only returns 2 bytes. Since I am trying to return ASCII data, it needs 14
bytes per sample of data;
>> char(data_raw(1:10+5*14-1))
ans =
#800107519-2.26131e-001,-2.26131e-001,-2.01005e-001,-2.26131e-001,-1.75879e-001

see attached test2.m octave script for further details.

With an older version of instrument-control it used to return all the data.
Since then I upgraded the computer from Unbuntu 16.x to 18.04
The firmware in the scope was upgraded
And of course instrument-control was updated.



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File Attachments:


-------------------------------------------------------
Date: Sun 26 Apr 2020 11:44:27 PM UTC  Name: test2.m  Size: 2KiB   By: None

<http://savannah.gnu.org/bugs/download.php?file_id=48947>

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