areaDetector/asynPortDriver order of parameter initialization

[Irie Railton - STFC UKRI via Tech-talk <tech-talk@aps.anl.gov>]

Hello EPICS community,

I'm working on an areaDetector driver for PIXCI frame grabbers and associated cameras (ADPixci), and I'm having an issue with accessing uninitialized parameters.

On initialisation my asyn parameters are being processed, and then I have a thread that handles the changes and passes them on to the camera. For some of my parameters, processing a change involves getting the value of another parameter but for a couple of them this other parameter is not yet initialized so it is giving me an asynParamUndefined status.

So I had a look into ADCore and I can't figure out what causes the parameters to process on startup, and why the order of initialization is the way it is.

So my question is: how is the order of parameter initialisation decided and can it be modified?

Kind regards,

Irie Railton

Software Engineer

Software Controls Group

CLF Engineering Division