FLIR camera PV cam1:NumImages_RBV does not match cam1:NumImages about adspinnaker

[MarkRivers]

I have seen the same behavior. It appears the Multiple mode has a minimum of 2 images. If you want just 1 then use Single mode.

[MarkRivers]

This is a feature of the camera firmware , not the EPICS software.

[ronpandolfi]

The issue we're encountering is actually not limited to Multiple mode. Even in Single mode, the following returns an unexpected result:

$ caput 13SP1:cam1:ImageMode 0
Old : 13SP1:cam1:ImageMode           Multiple
New : 13SP1:cam1:ImageMode           Single
$ caput 13SP1:cam1:NumImages 1
Old : 13SP1:cam1:NumImages           1
New : 13SP1:cam1:NumImages           1
$ caget 13SP1:cam1:NumImages_RBV
13SP1:cam1:NumImages_RBV       2

The returned value is always at least 2.

[MarkRivers]

The returned value is always at least 2.

Yes, because that GenICam feature for NumImages only applies in Multiple mode. So it is never allowed to be less than 2.

[ronpandolfi]

I see. So this behavior is unique to the design of this driver, and not consistent with other AD devices? A side-effect of this is that I'm unable to acquire a single image through Bluesky. Whenever requesting one image frame, I end up with 2. How could this behavior be corrected?

[MarkRivers]

Bluesky should be using Singl mode when it want to acquire a single image. There are many SDKs for which that is simpler and more efficient than Multiple mode with NumImages=1.

We could also change ADGenICam so that if NumImages=1 it changes to Single mode. But then when NumImages is changed to >1 should it automatically go to Multiple mode? What if the user does not want that?

[MarkRivers]

It is not really unique to the design of this driver. The GenICam feature is AcquisitionFrameCount, which GenICam says must be >=1. But FLIR seems to limit it to be >=2, so it is a function of their firmware design.