Experimental Physics and
Industrial Control System

[email protected] · Fri, 13 Dec 1996 18:19:19 +0100 (MET)

Jim writes:

>I've been reading the IP support mail messages over the last couple of
>hours on tech-talk and I guess I have a question about all of it and a
>few comments.  I've read through all of your stuff, so I might as well
>throw my stuff out here too.

>I see three basic IP developments in process, maybe four:
> 1) telescope community (Andrew/Peregrine)
> 2) IRM developments and other (Matthias/DESY/Fermilab)
> 3) HiDEOS

In fact there are several ways to communicate with serial IP's:

-telescope community (Andrew/Peregrine) partly using HIDEOS
-DESY using CDI (which runs under VxWorks and support single and multiple CPU's)
-ANL HIDEOS
-BESSY - there way to do it

There have been enough arguments about HIDEOS/CDI and others.
It's not religious. There are finacial arguments: (HIDEOS does not need VxWorks licences)
Technical arguments etc. and I do not believe that any programmer who did this job will 
want merge his code with another one.
The actual version of CDI is now optimized for asynch. I/O and can handle even bulk data 
with might be connected to sevel(hundred) of EPICS records in a most efficient way. This 
development took Gabor a lot of time to optimize the code. I am sure we will not want to 
move to any other code.

You as the EPICS community have tha chance to pick what you like. 
Looking at the history of CDI - this in fact was already running 1 year before HIDEOS was 
developed because we already used it under VAX-eln (who ever knows this 'strange' 
operating system). But this only for clarification.

The arguments for the register-based drivers for IP modules are surely true and  in fact 
the drivers written for the IP-modules in the Fermilab-IRM's are NOT using CDI but are 
written in the same way as any other VME-IO drivers. 
Are there so many common aspects on the IP drivers that you might want to standardize on? 
What's the difference to the VME drivers?
Well - it would be worth thinking of something like auto-configuration of IP modules...
Is this the idea?

We need in general some standards:
for serial IO we already have at least 4
for direct IO ?
- auto configuration?
- others?

Matthias

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System