sample data from two channels simultaneously in PCI 5922

[andycui]

Dear all: 

I want  to sample data simultaneously from two channels in PCI 5922. The niscope driver has some example VB programs to sample data from one channel, for example, the "save to file ", the program works well to sample the data from one channel.  When I modify it to sample data simultaneously from two channels, I always get error.  I attached the sample program here and what I tried to modify is the "channel name" and "waveform()". The Driver also provide sample labview program "niScope EX save to File" in niscope driver V3.4 to sample data from channel 0 or channel 1 or 2 channels together in PCI5922. When I run it, there is always an error message:

Error occurred at:  niScope Multi Fetch.vi:1
<err>Driver Status:  (Hex 0xBFFA2003)
Maximum time exceeded before the operation completed.
Status Code: -200284

When I use other sample program to sample data from 1 channel without the "niscope multi fetch" unit, it works well.  so I seek your help on how to sample data from two channels simultaneously. Thanks.  
Regards
Andy

[Paul_C.]

Hi Andy,

The "save to file" example isn't programmed to work with 2 channels.  I recommend taking a look at the "ConfiguredAcquisition" example which is specifically programmed to work with 1, 2, or both channels.  In regards to the LabVIEW application, I verified that the "niScope EX save to File" does indeed work.  That error typically occurs when you're not receiving a trigger and the fetch times out because theres no data.  Do you have a signal connected to the scope?  That example, by default, uses an analog reference trigger on channel 0 at 0V.  If this trigger is never met, you won't see any data and you will eventually get an error.  The "niscope multi fetch" unit or vi is what is gathering the acquired samples from the card.

Regards,
Paul C.