LabVIEW control Interface 54645d, Please Help!!!

[johnhe]

Hi, I am having trouble getting two trace signals or to at least get signal from channel 2 on my labview interface, I get the two signal traces on the physical oscilloscope and when I try and execute the labview interface it only shows channel 1. I was able to save waveform data into an excel .csv format file and to get one signal (channel1) but now I'm trying to get a second signal or if not possible, to at least get a channel 2 signal on another window, Please Help, been spending time researching for solution but came to no solution and don't know how I can get this signal displayed. If anybody know how I can get this to work or if they can test it on a physical oscilloscope for themselves to see, I would really appreciate it. Please again I am asking for help. Thank You.

Currently working w/ Hardware: HP/Agilent 54645D Mixed signal Oscilloscope, Interface module 54657A module attached to oscilloscope, GPIB cable connected to PCI-GPIB card, using Function Generator HP 33120A Function/Arbitrary Waveform Generator.

Attached is a screenshot of the hardware (oscilloscope/function generator and Interface front panel) and my current VI. Please if you can help me get a second signal from channel 2, I will APRECIATE this thank you.

John

[Blizzard]

Hi John,

After looking at your code,  it appears that you have several locations that limit your output only to channel 1 or channel 2 selectively. When you get no reading from channel 2, do you have the trace number set to 2 and the Source set to Analog 2 so that your case structures allow you to read from channel 2 and save to channel 2? It appears from your picture that the two controls are set differently.

Best regards,

Anna

[johnhe]

Hi,
Yes, I have tried to put them to analog 2 and it still does not work, I tried putting analog config.vi to channel 2 constant and the digitize.vi to channel 2 and channel1/2, and read waveform.vi to read source analog 2 and have created another read waveform and put channel 2 but still no solution. Please let me know what I should do.

[johnhe]

Attached is the current VI I have. I have tried putting analog 2(channel2) to the VI's that have source terminal but this does not work, do you have any more ideas I could use to display waveform? Maybe I need to download something else? or what do I need to do to display two signals on this VI ??

[Blizzard · Accepted solution]

Hi John,

Since you are using a Scope and an IVI driver, you will not be able to use the Read waveform VI to acquire both waveforms. However, you can use the Initiate and Fetch VIs to acquire the waveforms from both channels. You will first use the Initiate VI referring to both channels, and then you will follow that command with the Fetch VI for each channel individually. This KnowledgeBase article I've linked below gives a more thorough description of why you cannot use the Read Waveform VI for both channels:

Using a Scope IVI Specific Instrument Driver to Acquire Multiple Waveforms Simultaneously:http://digital.ni.com/public.nsf/allkb/9FC2291D4CF6851A862567B30050AB12

I hope this helps explain the behavior you are seeing.

Best Regards,

Anna

[johnhe]

I know I haven't replied to this message for a while, I gave a short break but I'm back on this project to finish a Control Interface that would let me get two waveforms and capture the data in a .csv format to use later. Please let me know if I should ask on another new page or if I can continue on this one.I think I would need to start from scratch for this one since I need to do a user friendly interface that shows to signals(waveforms) with a GPIB connection. The question I have is How can I do this with an easy overview of what I have to do exactly. Thanks alot for the reply. 

[WenR]

Hello johnhe

Since this thread has ben closed as a solved forum, I think it would be better if you open a new thread with this issue. Thanks!

WenR