Screen capture for Tektronix 2232

[rachel-d]

Hello. I am trying capture the screen image and data points from a Tektonix 2232 oscilloscope with LabView. I have downloaded the driver for a 2230 from here http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E96C2659CE034080020E748... because there is only a LabWindows not LabView driver for the 2232. The driver can connect to the scope but it always gives the error "Channel switch setting does not match scope setting". Does anyone know how I can fix this? I have tried all the available scope settings but it always gives that error.

[Dennis_Knutson]

That's a very good example for how NOT to write an instrument driver. I can see why the download page says it's not supported. There's only the one VI that communicates with the scope and one that converts the data returned. The error is being generated by the second frame of the sequence structure in Tek 223x. The query 'VMO?' is sent in frame 1 and parsed in frame 2. It expects to see returned VMO CH0/ALT/ADD/CH1/CH2;. You could stick a probe on the output of the GPIB in frame 2 to see what is actually being returned and then modify the code. You might be better off starting from scratch and using the develop tools to create a much more robust driver. Information, tools, and a tutorial can all be found under the Develop section at http://www.ni.com/devzone/idnet/default.htm. You also have the option of using the Instrument I/O Assistant.

If you need some help in modifying what you have, start by doing the probe I mentioned and post back with the results.

[CamWade]

Hi,

I have recently uploaded the above (unsupported) program, and I've got it working fine for simple tasks.  I wish to do an average of a number of runs (anywhere from 50 to 100) in the averaging acquisition mode.  It seems as though the program 'times out' after approximately ten seconds.  I'm using an optical chopper for my external input for my triggereing device.  Depending on the frequency of the chopper I can get up to about 25 samples before the program ends.  Regardless of the frequency of the chopper, the program will only collect data from the scope for about 10 seconds (it seems as though the program 'times out' after approximately ten seconds). I've tried looking through the program for any time delays etc... but can't seem to reason why this is happening.  Any help would be great.

Thanks,

Cam