Re: IOC options

[Heinrich du Toit <heinrichdt@tlabs.ac.za>]

Hi again

>From what I gather in the replies I got on my previous post I think it
is a good idea to explain our situation more in full.

We are currently investigating using EPICS as a control system at
iThemba LABS. This obviously has many advantages, especially since so
much development has already been done.

Now the big problem is that we need to get our current systems over to
epics in a easy but also fairly-cheap fashion. Don't have million for
this. So we can't replace existing hardware, don't have time, man-power
or money for that.

The bad news is that most of this hardware is custom made... and is
fairly old. This includes just about everything from powersupply
controllers to vacuum controllers to beam monitors ect ect.
The one advantage is that most of this runs in crates on a bus we call
SABUS (once again custom made) in basic form it is a parallel
communication bus with data and address lines and some control signals.
This is also a system that connects several of these crates together.
Then you have a differential system that has an 8-bit data bus and about
4 control signals.

So I want to have a cheapish system to communicate with this stuff. in
some or other manner. And then I will need to write tons of code to
communicate over this SABUS system(s) to the different cards. Most of
them are fairly easy so that ain't a problem.
But I think this will need to be done at a fairly low level - device
driver sort off?

This is why I had the ARM idea...
The ARM is fairly small (compared to a pc) but can still run linux,RTEMS
and have network access (needed by EPICS offcourse)
And I figured It might be easier to get I/O access on the ARM than a pc
platform.
And then I can maybe make my own little PCB with ARM,ram,flash,network
and I/O connectors? 
I managed to create fpga boards so this can't be that much harder :)

The part I'm really unsure about is how to get Linux onto that arm, and
the EPICS onto that linux-arm and then to get that EPICS to communicate
on the ARM I/O pins.

All help and ideas are obviously appreciated!
Thanks to those that already responded

thanks.
-Heinrich du Toit

On Wed, 2007-06-13 at 11:55 +0200, Heinrich du Toit wrote:
> Hi
> 
> We have just started investigating using EPICS :)
> So far so good.
> The one problem we have is that we have tons of existing hardware (lotsa
> it is custom made) that I will need to interface. Luckily most if this
> hardware works on a fairly simple bus interface (once again custom made)
> 
> I was thinking that the following might be options:
> 1. To have a small linux pc (pc104?) and put in some or other card
> (maybe NI) to interface the hardware and run the IOC software on here
> Having a strict real-time system isn't really important. 
> The problem I have with this setup is that I will probably have to
> develop some in-between interface to go between the pc and the hardware.
> Or I need to figure out how to get NI cards working under linux.. but
> even with that we need in-between devices.
> 
> 2. The other option I like is the idea of using a ARM processor.
> Now If I'm not mistaken I can run EPICS on Linux on ARM - correct?
> What do I need on my ARM system for this to work? In terms of flash/ram.
> How difficult will the be to get working?
> Or maybe somebody has already done something similar? 
> 
> I appreciate any help!
> 
> -Heinrich du Toit
> iThemba LABS
> 
> Ps. Is there anybody in South-Africa making use of EPICS?
> 
> 
>