Re: New EPICS User Questions: (1) Microcontrollers (2) Data-data pipeline?

[Jeong Han Lee via Tech-talk <tech-talk at aps.anl.gov>]

On Wed, Feb 24, 2021 at 1:35 PM Feister, Scott via Tech-talk
<tech-talk at aps.anl.gov> wrote:
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> Hi EPICS users,
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>
>
> I am beginning to explore the idea of using EPICS as the basis for automated-control data feedback loops in the context of high-intensity-laser plasma experiments. The experimental repetition rates vary between 1 Hz and 1 kHz, depending on the facility. Typical devices in the pipeline include cameras, fast digitizers, slow digitizers, motor controls, oscilloscopes, etc. Recently I have been also been working on developing custom embedded systems based on microcontrollers, that can do some early on-board distributed pre-analysis of data.

If you select and find the existing EPICS support equipment in terms
of cameras, fast digitizers, slow digitizers, motor controls,
oscilloscopes, etc, you could save a lot of resources within the
experiment lifetime.

> As I explore EPICS, I have a couple of introductory questions for which I think you could quickly help.
>
> Is there support for using microcontrollers as EPICS clients? E.g. ethernet-enabled Arduinos or STM32 Nucleo Boards.

It depends on what "support" definition is. It doesn't support
ethernet-enabled Arduinos, but it does support embedded "Ethernet.h"
into your own EPICS software (called it naively Driver). Then you have
to write your own specific IOC application for the production.

> Am I correct in my understanding that EPICS is meant primarily for managing systems data and systems control, rather than the core scientific data from an experiment (e.g. bandwidth-heavy high-speed cameras with 300 Hz image updates, fast digitizers, etc)?

You can check what AreaDetector supports according to Mark's email. I
am sure you will be surprised.


> If my understanding is correct, do you know of any similar projects relating to managing the data pipeline for acquisition and storage of high-bandwidth, non-feedback-control scientific data?
>

You may check the following two papers, which were published 15 years
ago. That is the KSTAR project. After this success, ITER project
"picked" the EPICS as their fundamental control / data acquisition
system based on my understanding (it may be wrong). Dr. Kukhee Kim may
explain them if he can see this thread.

https://www.sciencedirect.com/science/article/abs/pii/S0920379606001116
https://www.sciencedirect.com/science/article/abs/pii/S0920379606001104

Meanwhile, the community developed the new protocol pvAccess in order
to handle more flexible data structure within EPICS. The protocol is
ready, but other features are not the same user-friendly stage as what
EPICS 3 (Channel Access Protocol) does.

HTH,
Han



>
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> Thank you!
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>
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> Scott
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>
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> Scott Feister
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> Assistant Professor, Computer Science
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> California State University Channel Islands
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> scott.feister at csuci.edu