Experimental Physics and
Industrial Control System

Rod,

 

I was involved with a such a systems (and we needed to address that very concern that our regulator had). 

 

The two places where the alarm goes off Is in the field and in the control room. 

 

One could argue that the alarm going off in the field plays a safety role if it is purpose is to direct staff to leave the area.  Redundant and diverse solutions using both horns and lights would be a nice way of handling it.  There are some pretty nifty IEC 61508 certified monitors and horns on the market.   Personal preference I would try to do that one independently of EPICS as the hazard and risk analysis is simplified.

 

One could potentially argue the annunciation in the control room is not safety critical but safety related.  The safety issue is resolved if the local horn is going and staff have left the area.  Generally I would use a separate app with watchdogs etc.  I am aware of one lab with the regulator required that app to be running as a condition of operating the machine.

 

I think it comes down to how you do the Hazard and Risk Analysis and the mitigation you have in place. 

 

 

Elder Matias

Mighty Oaks

http://www.mightyoaks.com

 

 

----------------------

Subject:	RE: Alarm annunciation with ALH and other PC based systems
From:	"Munro Jr, John K." <[email protected]>
To:	Rod Nussbaumer <[email protected]>, epics Techtalk <[email protected]>
Date:	Wed, 14 Jan 2015 22:25:30 +0000

Hi Rod,

 

Background noises and alarm floods are also potential problems, so if alarms are really important, audio needs to be supplemented with visual alarms (i.e., a multi-factor approach needs to be considered).  Relying on audio alarms alone is probably not going to be satisfactory because someone is always going to be adjusting something to suit individual preferences.  Are you doing any alarm filtering?

 

John Munro

ORNL

 

 

-----Original Message-----

From: [email protected] [mailto:[email protected]] On Behalf Of Rod Nussbaumer

Sent: Wednesday, January 14, 2015 4:27 PM

To: epics Techtalk

Subject: Alarm annunciation with ALH and other PC based systems

 

Hi All:

 

Sorry that this isn't really an EPICS question, other than the tenuous

connection via Alarm Handler.

 

The question has been raised here about how to ensure that the audible

alarms from Alarm Handler are always audible. A number of places exist

where this can be disabled. The speakers can become faulty, the

wall-wart commonly used to power the speakers can become disconnected or

faulty, the volume control on the speakers can be turned down, the host

OS software controls can be turned down or muted either through accident

or software fault, audio cables can become faulty, and sound card

hardware can become faulty. Most of these will manifest only in silence.

 

Has anyone undertaken measures to monitor any of these components in

some way, or implemented hardware which is not subject to the common

frailties of commodity audio equipment used for control room alarms?

 

Any suggestions cheerfully accepted. Thanks.

 

Rod Nussbaumer

E-Linac Controls, TRIUMF

Vancouver, Canada.

 

 

Elder Matias, BSc,

CEO  T: 250.386.9398 x203 | [email protected]
MIGHTY OAKS  Business ~ IT ~ Community  27 Burnside Road West Victoria | TF: 866.386.9398 | www.mightyoaks.com