[Dsg-halla_gem] [EXTERNAL] Re: Re: Add an ADC to RPi for gas flows?

[Brad Sawatzky]

Thanks Steve, found it.  Not that it matters much, but why is the RPi
pushing to a softIOC on adaqsc rather than serving the PVs directly from
the RPi?  Is it related to the RPi being on a dev subnet?


Marc/Jack:
  There is a new PV 'HAGEM:SBS:gas:mix' that can be populated from the
  RPi if you like.  I'm assuming that the value pushed up will be the
  Argon fraction in percent (between 0 and 100), but that unit
  conversion from the ADC readback can be done anywhere of course.

-- Brad

On Fri, 04 Mar 2022, Stephen Wood wrote:

> Brad:
> It should just be a matter of adding new signals to the IOC iocGEMGas
> running on adaqsc.  The wiki notes for the SBS EPICS have moved from the
> Hall A wiki to https://sbs.jlab.org/wiki/index.php/SBS_EPICS
> Steve
> 
>   On Mar 4, 2022, at 2:02 PM, Marc Mcmullen <mcmullen at jlab.org> wrote:
>   Brad,
> 
>   Excellent!
> 
>   Regards,
>   Marc McMullen
>   Sr. Instrumentation Designer
>   Detector Support Group
>   (757) 269-7738
> 
>   From: Brad Sawatzky
>   Sent: Friday, March 4, 2022 2:01 PM
>   To: Marc Mcmullen
>   Cc: Jack Segal; dsg-halla_gem at jlab.org; Patrizia Rossi
>   Subject: [EXTERNAL] Re: [Dsg-halla_gem] Add an ADC to RPi for gas flows?
> 
>   Hi Marc,
> 
>   You should probably coordinate IOC updates with me (although Steve is
>   around to support).
> 
>   -- Brad
> 
>   On Fri, 04 Mar 2022, Marc Mcmullen wrote:
> 
>   > Hi Jack,
>   >
>   > I'll be at the lab on Monday to get the ADC. I'll discuss this
>   > with our group and come up with a solution on this. Additionally,
>   > I'll probably set up a meeting for the GEMs sometime next week so
>   > we can talk about analysis of the gas.
>   >
>   > This will require an additional PV (I'll probably want a few
>   > extras for expansion), I use to coordinate that with Steve. Is he
>   > still  handling the IOC updates?
>   >
>   > Regards,
>   > Marc McMullen
>   > Sr. Instrumentation Designer
>   > Detector Support Group
>   > (757) 269-7738
> 
>   > From: Jack Segal
>   > Sent: Friday, March 4, 2022 1:38 PM
>   > To: Marc Mcmullen
>   > Subject: Add an ADC to RPi for gas flows?
>   >
>   > Marc,
>   > We are adding a Binary Gas Analyzer, see the attached picture. It
>   > has an analog output.
>   > Can we try to add an ADC to the I2C string to read this out with
>   > the mass flow sensors?
>   > I have some DIN rail mountable 16 bit ADCs.
>   >    This allows us to monitor the gas mixture ratio.

-- 
Brad Sawatzky (he/him), PhD <brads at jlab.org> -<>- Jefferson Lab/ Hall C/C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov