2D Data

[youcann]

Hi,
i'm quite new to EPICS, so this is maybe a dumb question:

How can i use a 2D array as record in pythonSoftIOC?
This would be much simpler than the EPICS areaDetector in C as i already have my video frames in python.

Thanks!

[Araneidae]

Have converted this to a Q&A discussion.

The answer is perhaps frustratingly simple: EPICS, at least without the more advanced features of PVA (EPICS 7), does not support 2D arrays. What you have to do is flatten your 2D array into 1D for transport and reshape it back to 2D at the receiving end.

[youcann]

Thanks for moving to Q&A

So with pythonSoftIOC supporting PVA, i could just try to use a 2D array, right?

[Araneidae]

Well... but pythonSoftIOC is oblivious of PVA, so I'm afraid, no.

[thomascobb]

Yes, PVA sits as a layer on top of existing EPICS records (which pythonSoftIOC produces), so although PVA can serve an NTNDArray, there are no records that can produce it natively. Even an NTNDArray is still a 1D waveform, just with metadata to allow the client to reshape it. It might be possible to use QSRV info tags with a 1D waveform record to add the extra metadata, but I haven't tried it.