Camera Synchronization

[kjjohnsen]

I'm having problems synchronizing the cameras. Sometimes it works, but it's infrequent. Can someone elaborate on the process? Thanks

[Jim]

Can you tell us what camera type you have and how you have them hooked up? Look for a picture diagram in the Quick Start Guide.

If you are hooked up like the QSG, then some issues can be; making sure you don't "complete the chain" by hooking the start Master to the end camera, it is an open loop. Also if you have too many cameras hooked into a not so good USB hub, the frame arrival times can be bad, even if the cameras are sync'd. If you aren't using the sync cables, then there is no good way to help the problem, as software sync is subject to each computer, and not that reliable.

Hopefully this helps some.

[kjjohnsen]

I have V100's, just two of them, the sync cable is hooked up as specified in the QSQ. I'm not sure I know what you're referring to by the "start Master to the end camera" can you clarify? Thanks.

[Jim]

The Master is the 1st camera in the sync chain and the end camera is the last one.

If you have 2 and the Out is connected to the In, you should be good to go. Perhaps it is a PC performace issue, or a bad hub, we have seen that.

[Birch]

Can you describe what you mean by synchronization problems? Are you referring to exposure timing, frame arrival times, or maybe frame IDs?

[kjjohnsen]

It's hard to say. The main issue I'm having is that the frame ids do not line up, although sometimes they do, it seems intermittent, but mostly they do not.

[Jim]

This could be a computer system issue, the system being too loaded and that causing delays in the frames being delivered, or a USB hub that isn't working as it should.

More information on your exact setup would be useful; computer type, USB hub configuration, CPU load and how you know the frames aren't coming in sync.

[kjjohnsen]

It would be easier if you had c++ sample code that synchronized two cameras. The way I'm doing it currently is

cameraCollection->Synchronize(), which btw, returns S_OK regardless of the actual result.

I know the frames are not sychronized is by looking at the result of

myCamera->GetFrame(INFINITE,&frame1)
myCamera2->GetFrame(INFINITE,&frame2)
if(frame1!=NULL){
frame1->get_Id(&frame_id);
cout get_Id(&frame_id);
cout << frame_id << endl;
}

I'm going to check to see if system load is the issue though, because my problem is intermittent, it makes sense that it's something that may be variable.

[Jim]

hello:

I will have one of our software developers comment on the code, but from a hardware perspective, sync is automatic, if the cables are hooked up, then the cameras are in sync. The only thing that could cause them not to appear in sync is the frame delivery over USB, due to load or some other problem. The actual cameras are in sync with hardware signaling.

[kjjohnsen]

Alright, thanks, I look forward to hearing from your software developers.