Re: Hardware needed to setup an IOC

[Andrew Johnson <anj@aps.anl.gov>]

Hi Andrew,

Apologies for the delay in approving your message, apparently the other tech-
talk moderator was also off earlier this week.

On 2011-06-14 Andrew Cox wrote:
> I am a newbie to EPICS and I wanted to see what kind of hardware is needed
> to install a soft IOC. I wanted to control upto 25 LAN/ GPIB/ USB devices
> with more in the future.
> The devices include Power supplies, oscilloscopes, Signal generators, EPICS
> supported other test equipment.
> 
> Will a dell computer with Red hat lInux and a few cisco network switches
> work for so many devices or do I need a server class computer ?

The minimum requirements for a soft IOC are pretty small, as EPICS IOCs were 
originally designed to be run on MC68K-based embedded CPU boards running 
vxWorks with as little as 4MB of RAM.  That's probably too little RAM 
nowadays, but we still have vxWorks IOCs here running with only 8 or 12MB.  On 
Linux anything that's capable of running a current desktop distribution should 
have no problems. The size of machine you need will depend on how much data 
you're going to store and process, but for the kinds of things you're talking 
about I think you'll have to do a fair bit of development work before you fill 
up a standard desktop.

One advantage of EPICS is that it's easy to split up a control system between 
multiple machines and to change that split as needed as long as your I/O is 
all network-attached.  Here at the APS we have a single system that runs about 
30 soft IOCs on 1GB of RAM, but we could move as many of those as we need to 
other machines with no noticeable effect on the control system.

HTH, keep asking questions here!

- Andrew
-- 
Optimization is the process of taking something that works and
replacing it with something that almost works, but costs less.
-- Roger Needham