Syncronisation with Real time streaming

[Abibat]

Hi,

I am not sure if my post is in the right forum/section, so any advice will be useful.


Problem

I stream data cordinate points from Optitrack Arena into Matlab using the java method of receiving data packets.So Arena is simply running in the background. Voltage from a sensor is also obtained in matlab using a DAQ USB. The two information needs to be picked up at the same time/syncronised. Information from the 2 differnt sources is intended to be used to create joint angles with force information in real time. This updates the matlab graphics continously to display the required information. In terms of how this works, I have simply created a for loop in matlab which receives the arena data for each loop and the next line acquires the data from the DAQ. The problem is that there is a lag between acquiring both information, so I am looking for a way of using the syncronisation in Arena. It will work fine if I was recording data and postprocessing in Arena but I am using the exposure time option. I can pick up the times from the DAQ but I need to understand when the 3.2 value of the exposure time gets picked up and when it does not. I tried streaming in the background and ran the code to generate the exposure time but thier are times when it shows the exposure time as 3.2 and other times when the value becomes really small. I cannot seem to understand what causes the changes in the exposure time and how reliable this is. Alternatively is there any other way of obtainning the data at the same time. Also, does the Arena and Daq need to be run on a seperate computer, as this works for the recording level of the syncronisation.

Finally an Arena run time error occurs after a while. Apart from upgrading to 1.8 (which I understands resolves the issue but don't have a license for), is there any other fix to this problem?


Other Useful Information

Flexi V100 Cameras (12) + optihub
Arena version: 1.7.3
DAQ USB 6229


Thank you in advance


Abi

[jolsonsalem]

Abi, please email me at support@naturalpoint.com and I will help you resolve the run time error.