# Question on Multiple EV Sources

**URL:** <https://discuss.px4.io/t/question-on-multiple-ev-sources/34503>\
**Category:** PX4 Autopilot\
**Created:** [September 26, 2023, 7:37pm UTC](https://discuss.px4.io/t/question-on-multiple-ev-sources/34503 "2023-09-26T19:37:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jmltorch](https://discuss.px4.io/letter_avatar_proxy/v4/letter/j/c5a1d2/32.png) [@jmltorch](https://discuss.px4.io/u/jmltorch)\
**Post date:** [September 26, 2023, 7:37pm UTC](https://discuss.px4.io/t/question-on-multiple-ev-sources/34503/1 "2023-09-26T19:37:32Z")

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Hello,

I’m working with some dev drones that are running an onboard VIO system to push visual odometry messages to px4. I’m trying to integrate mocap data in conjunction with the VIO estimates. I was wondering if the EKF2 can concurrently handle incoming VISION\_POSITION\_ESTIMATE and ODOMETRY vehicle\_visual\_odometry messages when doing EV fusion.

Does anyone have experience using multiple sources of EV with px4?

Thanks

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<div class="post-metadata">

**Author:** ![jmltorch](https://discuss.px4.io/letter_avatar_proxy/v4/letter/j/c5a1d2/32.png) [@jmltorch](https://discuss.px4.io/u/jmltorch)\
**Post date:** [October 3, 2023, 8:45pm UTC](https://discuss.px4.io/t/question-on-multiple-ev-sources/34503/2 "2023-10-03T20:45:48Z")

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So I implemented my mocap server to send VISION\_POSITION\_ESTIMATE messages (#102) while my onboard VIO system was concurrently sending ODOMETRY messages (#331). Looking at the logs whenever I start sending the mocap data with the onboard VIO already running it caused the estimator to reset and stop using ev fusion for position, yaw, vel, etc…

Is this behavior expected? Is there no way to send two sources of EV position/odometry estimates to the EKF2 without causing it to reset?