Error #-1073807339 (Visa)

[Dan894]

Might this be caused by a slow USB to serial adapter? Is there any way to change the time out period in Labview?

[Danny Diaz]

Originally Posted by Dan894

Might this be caused by a slow USB to serial adapter?

Doubtful, but I'm not an expert in USB to Serial Adapters.

Originally Posted by Dan894

Is there any way to change the time out period in Labview?

Sure, but since the "Query for Result from Serial Port.VI" file contains the actual VISA read, we need to modify the calling source within the CMUCam2.vi file just a smidge. Follow these steps (I assume the CMUCam2 demo app is located in c:\CMUCam2, modify these instructions accordingly):

1. Open LabVIEW.
2. Click the "Browse" button under "Open"
3. Select the "CMUcam2 demo.llb" file within c:\CMUCam2 directory.
4. Double-click on the "CMUCam2.vi" in the list of VIs.
5. Press CTRL-E to get to the block diagram
6. The second conditional block is the main driving block - cycle through the conditions and look for calls to "query for result from serial port.vi", the icon will be a green VI with the words "Query Serial" on it. As input this VI has a timeout - just extend the timeout from 1 second (1,000 ms) to 10 seconds (10,000 ms) or whatever you want. There are several calls to "query for result from serial port.vi", so you might need to edit them all (I count 9 conditions with calls to "Query Serial" that you need to update the timeout).
7. Save the file.
8. Re-run the main application.

Good luck!
-Danny