Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Thu, 20 Jun 2013 22:05:57 +0000

I believe it also filters the messages so messages from different sources can be written to different files.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of J. Lewis Muir
Sent: Thursday, June 20, 2013 4:57 PM
To: Andrew Johnson
Cc: [email protected]
Subject: Re: New EPICS support module "feller", release 0.1

On 6/20/13 4:19 PM, Andrew Johnson wrote:
> Hi Lewis,
> 
> On 2013-06-20 J. Lewis Muir wrote:
>> Why would I want to use this wrapper instead of just using the EPICS
>> errlog facility directly?
> 
> See these tech-talk messages for context:
> 
> http://www.aps.anl.gov/epics/tech-talk/2013/msg01107.php
> http://www.aps.anl.gov/epics/tech-talk/2013/msg01115.php
> http://www.aps.anl.gov/epics/tech-talk/2013/msg01126.php
> http://www.aps.anl.gov/epics/tech-talk/2013/msg01256.php

Hi, Andrew.

Thanks for the context.

>> I didn't think the EPICS errlog facility provided a way to log to a
>> file;
> 
> It does if you connect it to an iocLogServer, see section 10.7 in the 
> AppDevGuide.

Right, I understand that.  But I'm (not very clearly) asking about the
case of writing to a file from an IOC using errlog and not depending on
another host.  Are you saying one can run iocLogServer on the same host
as the iocLogClient?  Will this work on vxWorks too?  I hadn't thought
of doing that.  This would be a new way (to me anyway) of writing to a
file from one IOC using errlog without depending on another host.

>> how does Feller log to a file using the EPICS errlog facility?
> 
> I assume it registers an errlogListener routine on the IOC by calling 
> errlogAddListener() (section 10.3 of the AppDevGuide) and writes the messages 
> it gets to the file.

OK, so here's where I could benefit from using feller: If my goal was to
write to a file using errlog from an IOC and *not* run iocLogServer at
all (i.e. not on the same host nor any other host), I could use feller
to do this.  I think I've got it.

Thanks,

Lewis

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System