I don’t think the Visca protocol is always bi-directional. It’s a very basic protocol for controlling PTZ cameras and not really something that should be used for camera tracking because of the (typically) low polling rate. 

Hi,

The VISCA protocol supports query commands that can be used for camera tracking and Aximmetry is theoritically able to use them. The camera I'm testing is supporting the VISCA protocol query commands subset. The Basic Calibrator is receiving this data as its UI is updated when rotating or zooming the camera but it is not processed. The markers are moving when rotating the camera instead of staying relatively in place.

All the best

Hi Eric,

Basically, when rotating your PTZ camera, you should see these rotation values change:

They are displayed in ° degree, so if you make a full spin with your PTZ camera, one of the values should change by 360.

A video of the basic calibrator while you are spinning the camera in different angles could help a lot in figuring out what goes wrong.

Usually, the accuracy of the PTZ camera's tracking and their tracking implementations are very unreliable.

Warmest regards,

Hi Eifert,

The data is well received. I'll se how I can produce the video ou required when being at the office,next week.

Best

Hello Eifert,

Here is the video:

https://we.tl/t-EgUyZhrtMC

Best regards

Hi Eric,

It seems from the video that the rotation only changes by the keypresses and not the actual movement of the camera. It is very likely that what you see in the calibrator is just the change in the input for your PTZ camera's rotation, that is why it always changes by 0.1 value. The camera likely provides these input changes for controlling purposes, like confirming the key press was received. However, this is not sufficient for camera tracking.
You might be able to confirm this if the camera can save positions. If you switch between these saved positions, you likely won't see any change in the data in the Aximmetry Basic Calibrator, as there will be no input from the controlling page.

Also, I couldn't find any information that this camera supports VISCA camera tracking, just that it supports VISCA camera control.

Warmest regards,

Hi,

I'll try to see if I can test the behaviour you're writing about. You can find the VISCA documentation of this camera on the Minnray site. It supports query PTZ parameters commands. Aren't they the commands you're using for VISCA tracking?

Best

I’m not aware of any camera that can use Visca for continuous camera tracking. The Query command is most likely just to get the current position of the head, as reported by it, but that doesn’t mean you will get smooth camera motion from it, just a static position. Also, it’s highly unlikely that these inexpensive camers have actual absolute encoders built in, so it won’t necessarily be accurate information either since it doesn’t take drift/slippage of the motors into account. 

Hi Eric,

No, we don't use commands for Visca tracking. There is no way to tell how much movement is 1 command.
The PTZ camera needs to send its actual rotation for the tracking to work.

Warmest regards,