Experimental Physics and
Industrial Control System

"Hu, Yong" <[email protected]> · Thu, 25 Oct 2012 14:14:33 +0000

I agree with Ben: no precise definition of softIOC. And there is no 'official' definition: I tried to search "EPICS Application Developer’s Guide" EPICS Base Release 3.14.12. But it seems there is no word 'softIOC'. Also I made a quick search on Release Notes R3.14.12.2 [1] and found a few words 'softIOC' and 'softIoc' mainly related to bugs or behavior change.

But I do have different view of '... softIOC as an IOC that does /not/ have direct access to "devices" ...'. Here is my case: I have made a compactPCI-based data acquisition system which has several cPCI digitizers and one cPCI CPU board. The CPU is running Debian/Linux. I create one IOC for each digitizer so that each digitizer is independently controlled and there are multiple IOCs parallelly running under Linux. In this case, I'd like to say those IOCs are softIOCs. There is a Debian package named 'sysv-rc-softioc' on NSLS-II Controls Package Repository [2] and we are heavily using this package to manage all our production softIOCs.

For me, softIOC has a very broad sense: the IOC(s) running on Windows could be softIOC(s); the single IOC running on vxWorks or RTEMS could be considered as a softIOC if it only contains soft records, if it accesses devices through network, serial, etc, if it ...    

Cheers,

Yong

[1] http://www.aps.anl.gov/epics/base/R3-14/12-docs/RELEASE_NOTES.html 

[2] http://epics.nsls2.bnl.gov/debian/  

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Benjamin Franksen
Sent: Wednesday, October 24, 2012 9:20 PM
To: [email protected]
Subject: Re: what are your definitions of softIOC and soft record?

Am Mittwoch, 24. Oktober 2012, 21:51:17 schrieb Jack Smith:
> Hello All,
>
> Here is my understanding of what is softIOC and what is soft record:
>
> 1. softIOC: any IOC (application/instance) running on Linux or Darwin 
> is a softIOC since each softIOC is an independent process and multiple 
> softIOCs can be running on the same physical machine. On the other 
> hand, only one IOC can be running on vxWorks or RTEMS so that I would 
> say IOC running on vxWorks or RTEMS is not a typical sofIOC. A softIOC 
> can control real hardware.

I always thought of softIOC as an IOC that does /not/ have direct access to "devices", accessing them only through network, serial IOC or some such. That you can have more than one on the same physical machine never occurred to me as a defining property for "softIOC".

I guess "softIOC" is a "soft term", there is no precise definition (and therefore I'd argue the term is rather useless).

> 2. soft record: any record not associated with real hardware is a soft 
> record. The DTYP field of a soft record is "Soft Channel" (default for 
> DTYP), "Raw Soft Channel", or "Async Soft Channel".

Yes. You could improve this definition by stating that the INP or OUT link must be of type pv_link (in teh sense of link.h in base), which includes any potential future "soft" support type.

Cheers
--
Ben Franksen

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System