External triggering of V120 Duo and monitoring for trigger using NatNetSDK

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MocapKCL2
Posts: 2
Joined: Fri Nov 09, 2018 5:24 am

External triggering of V120 Duo and monitoring for trigger using NatNetSDK

Post by MocapKCL2 » Fri Nov 09, 2018 6:09 am

Hi All,

I am trying to synchronise eyetracking data recording and mocap data recording. In order to do this, I want to send a TTL trigger from the eyetracking software on one PC to the I/O box of the V120 duo. Ideally, I'd like for matlab to start recording the mocap data (on a different PC to the eyetracking software) when this trigger is sent. We have tweaked the matlab sample in the SDK to allow us monitor and save the coordinate data for a rigid body but aren't quite sure what to get it to listen out for in terms of the trigger.

My questions are:

1) Is it possible to externally trigger the v120 duo via the BNC connection on the I/O box?
2) Is there a way to monitor for this trigger using the SDK?

Any help would be greatly appreciated as we are very new to all things motion tracking.

Thanks a lot,

Tegan

steven.andrews
NaturalPoint Employee
NaturalPoint Employee
Posts: 470
Joined: Mon Jan 19, 2015 11:52 am

Re: External triggering of V120 Duo and monitoring for trigger using NatNetSDK

Post by steven.andrews » Fri Nov 09, 2018 11:54 am

Hi Tegan,

The Tracking Bars are not capable of triggering Motive to record using a signal pulse. To trigger Motive remotely, you would either need to use the NatNet SDK's remote commands to start/stop recording, or you would need to send remote trigger packets.

Depending on the inputs the other systems are able to receive, it may be easier to reverse the setup and have Motive provide the recording trigger. It is possible for you to configure the output to send a recording pulse or a recording gated signal. These could be used to trigger the other systems when Motive begins recording.

Best,
Steven
--
Steven Andrews
OptiTrack | Senior Customer Support Engineer
help.naturalpoint.com
support@optitrack.com

MocapKCL2
Posts: 2
Joined: Fri Nov 09, 2018 5:24 am

Re: External triggering of V120 Duo and monitoring for trigger using NatNetSDK

Post by MocapKCL2 » Sun Nov 11, 2018 4:10 am

Hi Steven,

Thanks for getting back to me so quickly.

Just to follow up, can I check if we were to send a ttl trigger to the "sync in" BNC port on the I/O box, would we be able to detect this by monitoring the USB port on the PC? If so, could we then get matlab to look out for this change and then start storing mocap data once this change is detected? We don't necessarily need to start/stop recording with the trigger, but rather to start/stop storing of data.

Best,
Tegan

steven.andrews
NaturalPoint Employee
NaturalPoint Employee
Posts: 470
Joined: Mon Jan 19, 2015 11:52 am

Re: External triggering of V120 Duo and monitoring for trigger using NatNetSDK

Post by steven.andrews » Mon Nov 12, 2018 1:10 pm

My pleasure Tegan,

Unfortunately, the signal input from the I/O box is not accessible except through Motive.
Perhaps there's some way to intercept the signal from a USB device, but I am not familiar with any setups like that.

Cheers!
Steven
--
Steven Andrews
OptiTrack | Senior Customer Support Engineer
help.naturalpoint.com
support@optitrack.com

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