Experimental Physics and
Industrial Control System

Jörn Dreyer <[email protected]> · Tue, 02 Oct 2018 11:27:48 +0200

Hi Mark,

It looks a bit that I was not clear enough in my problem description:

Assume that I have one USB camera connected to my PC and on the Network there 
is some other camera from PrincetonIntruments. The driver will connect to the 
first camera it finds.
But which one is it? Its a random choice! Sometimes USB sometimes ethernet 
will win. So one does not know which camera will pop up.
That's why the discovery method was implemented, I guess. It will build a list 
of all available cameras, from which you can the select the one you want to 
operate with this driver instance.

In my dmesg output I find the following message:

usb 2-1.1: usbfs: process xxxxx (st.cmd) did not claim interface 0 before use

So that seems to be a bug in the PICam library.
I guess I have to contact Princeton Instruments with that.

Regards

Jörn

Am Dienstag, 2. Oktober 2018, 09:34:10 CEST schrieb Engbretson, Mark S.:
> I believe that this is the expected behavior of that area detector. You can
> have multiple real or simulated cameras configured, but you can only use
> one at a time. One of the display elements is a menu option of the possible
> cameras which allows you to pick and choice which one you want active at
> any given time. 

> I do not think that any single AD allows for multiple active cameras. The
> controls are not made for that. 

> If your case, you really need to configure yours as 2 different ones, and
> have each manually select for the particular one the you want - which only
> works if you do not have 2 of the same camera type.

> On Oct 2, 2018, at 02:00, Jörn Dreyer <[email protected]> wrote:
> 
> Hello,
> 
> I'm currently setting up a system that uses a PrincetonImaging PIXIS camera.
> 
 As these cameras use an USB interface I have to use the latest version of
> the PICAM library (5.1.2) from Princeton.
> With this library the driver connects at startup but looses the camera
> during 
 the initialization phase. In the hardware setup routine the driver
> registers a callback function for the PICAM_Discovery mechanism. This
> function seems to loos the communication over USB with the connected camera
> if another thread talks to the camera.
> Has anybody else observed this behavior? I could get around this problem if
> I 
 comment out the calls to the PICAM_AdvancedRegisterForDiscovery
> function. But then the driver is only able to use the first detected
> camera. If I would connect two, I can not select the one I want to use.
> 
> Regards
> 
> Jörn
> 
> 
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System