How is synchronization achieved in labview when using wireless USB sensors (micr

[Theo23]

How is synchronization achieved in labview when using wireless USB sensors (microstrain G-Link, Inertia Link) and a NI PCIe-1429 image acquisition card (used for video acquisition)

[Hillman]

Hi Theo23,

I hope your well.

The best way to synchronize your setup would be to use the trigger line of the frame grabber to trigger both the camera and your sensor. So at least the readings would be taken at the same time, despite the time the data taking different times to get back to the computer. This setup would rely on your sensor having a trigger input, does it?

If you would like to discuss this some more, could you tell me more about your sensor and setup.

Thanks for the post!

Regards,

[Hillman]

Hi Theo23,

I was just wondering how things were coming along with your application and I am just posting to check if everything went ok and whether the problem was resolved as I have not heard back from you.  If you have any further questions on this issue, please post back.

Regards,

[Theo23]

Hi Hillman, Thanks for your concern. I have not yet tried anything regarding synchronization since i am still trying to develop the labview program for the 2 sensors (Microstrain Inertia-Link and G-Link). I am having problems with storaging the data. I downloaded some VIs regarding these sensors and try develop them further (as much as i can).

[Hillman]

Hi.

Thanks for your reply.

Well do you have any specific isssues that you need help with, or maybe re-thread them to get more users to see your post.

Regards,

[Theo23]

Hi

It's been a while since I posted my query but there is progress. I have merged together two different VIs that I found through your website and forum (after testing them and changing and adding staff). The two sensors I mentioned before (Microstrain G-Link and Inertia-Link) are now simultaneously storing data in a tdms file. The problem is that after about 4500-5000 samples for 20Hz frequency, the frequency starts to drop and finally becomes half. I used 'wait until next ms multiple' to synchronize the frequency. There are 9 channels of data, together with 2 timing channels in order to calculate the frequency, in the resulting tdms file. My first thought was problems with buffering the data but after several attempts I did not accomplish anything. Do you have any ideas. Any information would be useful

Thank you

[Hillman]

Hi Theo23,

Thanks for your reply.

So your saying the loop iteration rate is slowing down after around 4500-5000 samples?

I feel it would be easier to debug this if you could post some code, preferably an example which generates this behavior your seeing in your project.

Kind Regards,