read a screen capture from an oscilloscope

[oyester]

I am interfacing with a number of Agilent and Tektronix oscilloscopes. At the moment I am using a TDS 6604 Digital Storage Oscilloscope. Our user wants us to put up a waveform and have the oscilloscope  measure and display the rise time and pulse width. Then he want us to do a screen capture and save the resulting bitmap file to a designated directory on his computer. I can do all of this except for one thing. I don't know how to read a bitmap file across a port. Can anyone out there help me?

[chris_amadasun]

Hello,
You will not be able to transfer the bitmap across the port,
you can however use the Print.vi to command the Scope to print out the display.

[SimonH]

oyester,

As Christian suggests it is unlikely that there is a direct way to export a bitmap through the instrument driver.  I wasn't able to find a programming manual for the TDS 6604 so I can't confirm that is the case.  If you happen to have a manual check and see if there is a command that would export a bitmap.

Failing that, have you considered doing the analysis and reporting in LabVIEW or LabVIEW SignalExpress?  LabVIEW has all the signal processing functions you need to be able to calculate rise time and pulse width and as the graph is generated on your PC it is trivial to save it to disk.  Using the scopes to acquire the data and doing your processing in software will probably save you some work when and if you need to swap out the hardware (it also makes it easier to switch between your Agilent and Tektronix scopes).

Regards,

Simon H
National Instruments

[oyester]

Thanks for the help. I was getting very frustrated.

This is part of a very large LabVIEW program. What we are doing here is user-requested verification whereby we create a pulse with a requested rise time and pulse width and then some one else (the ADC) verifies that we have indeed created such a pulse. It seems that we are going to have to save the files on the oscilloscope and have the users remove them with data sticks.

[Dennis_Knutson]

I'm not sure why doing a screen save of the front panel of your VI is not enough but just because there is not a function in the driver does not mean that a transfer from scope to pc cannot be done. Look in the manual for file transfer functions and find the function that actually does the screen print. A check with Tektronix tech support is probably worth doing since if anyone knows how to do it, it would be the maker of the instrument.

[oyester]

The first thing I did was email Tektronix. This was their reply.

Thank you for contacting Tektronix Technical Support. 
In most of our oscilloscopes, when automating acquiring a screenshot, there are several pieces of information needed, including which port the screenshot are sent to, the format and the orientation of the image. 

The image can be captured using these programming commands:

HARDCOPY:FORMat <PCX, PCXcolor, PNG, BMPColor, etc.>
HARDCOPY:INKSAVER <ON, OFF>
HARDCOPY:LAYout <LANdscape, PORTRait>
HARDCOPY:PORT <RS232, GPIB, ETHERNET>
HARDCOPY START

After these commands have been sent to the scope you then issue the command in LabVIEW to open a file to read the data from the port. 
 
Best Regards: 
Stan England
Tektronix, Inc.

[Albert.Geven]

Your best option stays with only reading the trace data, display this in a LabVIEW graph (examples are available) and the print the frontpanel of the vi.
It is the fastest communication, the best graph and no reading of an unknown format.

good luck

[smercurio_fc]

I suppose you can try to see if something like this will work (based on the commands you got from Tek):



The above assumes GPIB (as noted in the HARDCOPYPORT) command.

Message Edited by smercurio_fc on 05-22-2008 05:46 PM

[Zocchi]

I wrote an application that works with Tek VISA (I believe that it will work with NI-VISA).  It's called ZScope Screen Capture.

Once the instrument is selected, with a single click, it gets a bitmap image and copies it to the clipboard.  From there, you can paste it into any Windows application (Word, paint, etc.)

It is available on my website www.zocchisystems.com .

I tested it with Tektronix TDS/DPO 3000 through TDS 8000 series.

I hope that this helps.

[donicio.coriz@ddesc.com]

The only thing you needed to do is wait for ~6 seconds for the Hardcopy to complete on the TDS Scope.  You'll see the hardcopy window flicker on the scope.  When it is done flickering, then the entire Binary file is ready to READ.  Use the "VISA Read to File.vi".  This will allow you to save to a directory and name the file (*.bmp).  Works very well.  Set the Byte Count to 200000.