AreaDetector NDFileHDF5 dynamic frame-placement within an opened H5-file

["Sintschuk, Michael via Tech-talk" <tech-talk at aps.anl.gov>]

Hello EPICS-community,

 

as the title of this thread says, I’m wondering if it is possible to dynamically select where an incoming frame is placed within the HDF5-Files structure. For example, while capturing frames in Stream-mode with the default HDF5-Files structure layout, all incoming frames are placed to:

entry -> instrument -> detector -> data

 

Now I want to load an individual hdf5-layout.xml with the additional location “flat”:

entry -> instrument -> detector -> flat

 

Is there a way that I can switch (via an EPICS-PV) the location where the next frame is stored, either “entry -> instrument -> detector -> data” or “entry -> instrument -> detector -> flat”, while the h5-files is still opened? Example scan with a total of 1000 frames, all should go into one h5-file:

• h5-files is opened
• the first 20 frames are placed to entry -> instrument -> detector -> flat
• the next 960 frames are placed to entry -> instrument -> detector -> data
• the last 20 frames are placed to entry -> instrument -> detector -> flat
• h5-files is closed

 

In the AreaDetector user-guide there is the following section:

https://areadetector.github.io/master/ADCore/NDFileHDF5.html#selective-positional-placement-of-individual-frames

I switched on the Position mode and put Index N to 0 (or 1) and put Name N to “flat” but I get a Write error status. I think I don’t understand the handling of the dataset dimensions within the h5-file and don’t know if my frame-placement sequence is actually realizable. Can someone help?

 

Thanks!

Michael

 

 

Michael Sintschuk
Bundesanstalt für Materialforschung und –prüfung (BAM)
8.5 Mikro-ZfP

Unter den Eichen 87
12205 Berlin
GERMANY

P: +49 30 8062-15063 (BESSY, Adlershof)

P: +49 30 8104-4065 (BAM, Steglitz)
michael.sintschuk at bam.de

michael.sintschuk at helmholtz-berlin.de