forums.naturalpoint.com

Dear all,
Is there a way for the optitrak software (rigid body point cloud software) to start data collection by receiving an external trigger (a TTL) from an external device (like via a serial port or USB)?
Most other systems like Optotrak allow for external triggering and I am wondering if something similar exists here.
Thanks very much,
Gene

Gene:

There is an external sync out mechanism from the V100 camera, out of the last camera in the chain. We are working on adding in trigger support and other more advanced sync features. We realize this is a very important feature to add and the cameras do have the capability to do what you ask, we just need to upgrade the firmware.

We are probably about 30-60 days out on this upgrade to the V100 cameras.

Jim

Hi Jim,
Thanks. If I understand correctly, the In-trigger upgrade (free?) is a couple months away from being released In the mean time, is the output from the last camera a TTL? If so, is it upgoing or downgoing and what is the pulse width? Is it just a matter of throwing on an adapter (I need a BNC output) and plugging the last camera to one of my output devices ?
Thanks,
Gene

Here is a previous rthread that covers the current external syncing signal

http://forum.naturalpoint.com/forum/ubb ... #Post28456

Hi,
I am able to receive the sync OUT trigger from the last camera in the chain. However, the sync out signal is activated once the cameras are synchronized. However, what I need is to have a common 'time zero' between the optitrak data collection and other devices (I need these to be synchronized with each other). Can you please suggest how I can do this? I recall that you were going to release an update that allowed the user to trigger the camera's data collection. Is this released yet? Other solutions?
Thanks,
Gene

That feature should be part of a future software/hardware update

Vincent,
Jim mentioned in October, 2008 that you guys were about 60 days away from this upgrade....however, we are now almost in May. Any idea when this will be available?
Gene

Hello:

Darn those forum posts that show how fast time goes by!

We do think that a sync upgrade is due for the V100 camera and we are actively working on it. It is now a project that includes other development work, so it has taken longer. I suspect we will have the update out in 60 days or less, really.

I understand what you need as far as a "zero time", so you can reference to other devices. We do plan to support this in some fashion with the new release.

In the mean time, I have seen users employ some unique techniques to sync their data. They use the 100hz output sync to get each frame time, and then they use a master event to get the zero time, such as dropping a reflective material covered ball that is tracked, and you can see when it hits in Arena and also on force plate data. Others have used an IR LED that is triggered by the other devices and Arena can see it as a marker that shows up in a specific frame. Finally, you could decode the rest of the sync signal, not just the frame, but the Frame ID, which is 8 bits so 255 frames at 100hz is about 2.5 seconds, and you have that much time from pressing play to align your data, it is the window to align within, if you can decode the 8bit values somehow.

Maybe these ideas will work for you, but we understand what you need and we will get it done, things just take a longer than I would like.

Jim

Hi Jim,
Thank you for your reply.
Those do indeed sound like clever alternative solutions. I really am waiting on the edge of my seat for this new update to have a more traditional triggering mechanism (listening for or outputting a TTL). It is pretty much the only thing holding me back from initiating my experiments...
How will I know when the release is available...is there a mass email to all users of the system or do I need to check back regularly?
I appreciate you guys making this a priority...
Thanks,
Gene

Hi,
I thought I'd check in to see when the release is planned for the next version that will allow external triggering. Also, I wanted to verify that this will be available for the rigid body tool kit and not just arena.

Thanks,
Gene