I agree that this area is complex, and the ambiguity of the standards don't
help.
Special immunity requirements exist for the following types of alarm systems
per the scope of EN 50130-4: intruder, hold-up, fire detection and fire
alarm, social, CCTV for security applications, access control for security
applications, and alarm transmission systems.
OK, but what is meant by "security applications"? CENELEC Report
R079-001:1996 defines CCTV surveillance system as: "a CCTV surveillance
system consists of camera equipment, monitoring and associated equipment for
transmission and controlling purposes which may be necessary for the
surveillance of a defined security zone." The report indicates that both EN
50130-4 and the ETSI EMC standards apply for RF CCTV products.
EN50132-7 provides guidance on surveillance zone determination criteria. "A
CCTV surveillance installation is designed to monitor events of fundamental
importance. These events might be hold up/theft, sabotage/vandalism, hazard,
evaluation, etc. Typical examples of monitoring applications are: perimeter
surveillance, access control, safety, property protection."
Is that clear as mud? Let's go on to ETSI and see what we find.
ETSI EN 301489-3 (EMC for Short Range Devices) specifies three classes of
equipment for immunity purposes. The most severe limits are listed for,
among other applications, domestic security, personal security and
baby/nursery monitor - non-domestic. These devices are listed as Class 1
devices because the result of too low performance is "physical risk to
persons or goods." Class 2 devices (lower immunity), which include domestic
transmission of sound and vision, may provide an "inconvenience to persons,
which cannot simply be overcome by other means." Class 3 devices (standard
immunity) including a "baby monitor" may provide an inconvenience to persons
which can simply be overcome by other means (e.g manual)."
Duh! So, take your best shot as to what the immunity requirements are for an
RF CCTV camera for baby monitoring.
Richard Woods
Sensormatic Electronics
Tyco International
-----Original Message-----
From: Gary McInturff [mailto:gary.mcintu...@worldwidepackets.com]
Sent: Thursday, January 03, 2002 11:34 AM
To: richwo...@tycoint.com; emc-p...@majordomo.ieee.org
Subject: RE: EMC-related safety issues
Richard,
A monitoring system is a convenience it is not a guarantee of life
saving functionality. It is a surveillance camera not a life support system.
If and infant, in this case, needs special monitoring because of some know
illness or just because you are really concerned parents, then move the
child next to your room or in it rather than relying and then blaming a
device with inherently less reliability than a human and especially and
alert parent. The camera is a convenience, not a substitute for
responsibility.
The camera manufacturer isn't responsible other than building a product
worth the cost of purchase, and that operates reasonably. They aren't
responsible for building a device that is failsafe - at least not in this
application. A failsafe surveillance system that is relied upon as the sole
life protection system better have redundancy and the 5 nines of reliability
and better. Like medical manufacturers they had better include in the
purchase price the cost of just and unjust lawsuits. People expect medical
equipment to do no harm and to not be the cause of death or injury. That's
the business they are in, and they do quite handsomely at it for the most
part. They have to do it because they are in that kind of business - life
support or protection, and are not just casual observers. People justifiably
want and expect them to have a product that works. None of this sounds like
a standard off the shelf camera system to me.
A simpler example that happen around here some years ago was a youngster
that was playing hockey with an approved hockey helmet. Long story short, he
was hit in the head with a puck and the helmet failed to perform its basic
function and the young man died. The parents were, in my opinion, absolutely
justified in suing the equipment manufacturer. because the product was being
used in its intended fashion.
Unless the camera manufacturer is making claims of life saving protection
rather than simple convenience monitoring they aren't culpable.
Obviously, my own opinions
Gary
-----Original Message-----
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Thursday, January 03, 2002 5:26 AM
To: emc-p...@majordomo.ieee.org
Subject: RE: EMC-related safety issues
Ken, let me address the specific case you mentioned - the RF camera used for
baby surveillance. In that particular application, surveillance for the
protection of persons, more severe immunity requirements apply. Those
requirements are either specified in EN 50130-4 or the particular ETSI
product EMC standard. A manucturer should understand that the product may be
used for protection of persons and apply the appropriate immunity
requirements. Failure to do so, could create a liability issue.
Richard Woods
Sensormatic Electronics
Tyco International
-----Original Message-----
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Wednesday, January 02, 2002 2:22 PM
To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org
Subject: Re: EMC-related safety issues
I have read a part of the IEE guide mentioned below. What I have read on a
paragraph by paragraph basis is fine, but I find the overall philosophy
deeply troubling. The tone of the document is that the manufacturer is
responsible for all uses or misuse of the equipment he sells in concert with
every other type of equipment made or that might be made at some time in the
future. This document is a trial lawyer's dream. It takes us from a
society in which a sale was deemed a transaction of mutual benefit between
equals to a society in which an Omniscient Producer must cater to the needs
of an ignorant, childlike Consumer, and in direct corollary, any misuse of
any product by any consumer is deemed proof that the Omniscient Producer was
profiting by taking advantage of a helpless victim. I realize this
document merely reflects this prevalent view, but the idea that an Industry
group would provide such a smoking gun for some trial lawyer to use in
defense of some poor misled swindled consumer is, to say the least,
troubling. To say that Industry standards don't go far enough, that it is
the responsibility of the Producer to be able to determine all possible
environments and failure modes that might ever occur is placing an
impossible burden and any rationale entity, upon reading this document will
immediately cease production of anything that could conceivably ever
malfunction in anyway whatsoever.
Case in point: A friend of mine bought one of these 2.4 GHz remote
miniature video cameras with integral IREDs and is able to monitor his
infant twins from his own bedroom, even in the middle of the night with no
lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in
some way and he misses something important happening in that bedroom. Is
the manufacturer of that video system responsible for any ill that then
befalls my friend's twins? I think not. But this safety guide says yes,
and places the manufacturer at risk.
----------
From: cherryclo...@aol.com
To: emc-p...@majordomo.ieee.org
Subject: Re: EMC-related safety issues
List-Post: emc-pstc@listserv.ieee.org
Date: Wed, Jan 2, 2002, 9:49 AM
Once again, John, you seem to be trying to give a negative impression about
the IEE's guide on EMC and Functional Safety (which you now admit you
haven't read) instead of simply saying what it is that you think is wrong
with it.
Of course I am passionate about the IEE guide - my colleagues and I spent a
long time working on it!
When I discovered you were criticising it to the emc-pstc of course I had to
respond - but I was not (and am not) trying to defend the guide, merely
trying to find out just exactly what it is that you (and your silent
'equally senior experts') don't like about it so I can get it improved.
I am sorry if my wordy emails give the wrong impression - the simple fact is
that I always write too much (as any editor who has had an article from me
will confirm!).
Once again I ask you - and everyone else in the entire EMC or Safety
community world-wide - to read the IEE's guide and let me have constructive
comments about how to improve it.
You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro
(- you only need to download the 'core' document for this exercise and can
leave the nine 'industry annexes' for later criticism).
I'll make it easy for anyone to comment even if they haven't read the Core
of the IEE's guide....
...the guide is based on the following engineering approach, explicitly
stated at the start of its Section 4 and duplicated below.
*****
To control EMC correctly for functional safety reasons, hazard and risk
assessments must take EM environment, emissions, and immunity into account.
The following should be addressed:
1) The EM disturbances, however infrequent, to which the apparatus might be
exposed
2) The foreseeable effects of such disturbances on the apparatus
3) How EM disturbances emitted by the apparatus might affect other apparatus
(existing or planned)?
4) The foreseeable safety implications of the above mentioned disturbances
(what is the severity of the hazard, the scale of the risk, and the
appropriate safety integrity level?)
5) The level of confidence required to verify that the above have been fully
considered and all necessary actions taken to achieve the desired level of
safety
*****
Please - anybody and everybody out there - tell me if there is anything
wrong with this engineering approach to EMC-related functional safety.
Involve experts you know who are not subscribers to emc-pstc too. Please be
as detailed as you can be.
If I receive no constructive comments about the above 5-point approach by
the end of January I will assume that the IEE's guide is on the right tracks
and will not need major revisions. You can send any comments to me via
emc-pstc or directly to keith.armstr...@cherryclough.com or
cherryclo...@aol.com.
Interestingly, my reading of IEC/TS 61000-1-2 leads me to believe that it
follows the same general approach as the IEE's guide.
Regards, Keith Armstrong
In a message dated 31/12/01 21:58:43 GMT Standard Time, j...@jmwa.demon.co.uk
writes:
Subj:Re: EMC-related safety issues
List-Post: emc-pstc@listserv.ieee.org
Date:31/12/01 21:58:43 GMT Standard Time
From: j...@jmwa.demon.co.uk (John Woodgate)
Sender: owner-emc-p...@majordomo.ieee.org
Reply-to: j...@jmwa.demon.co.uk <mailto:j...@jmwa.demon.co.uk> (John
Woodgate)
To: emc-p...@majordomo.ieee.org
I read in !emc-pstc that cherryclo...@aol.com wrote (in <17c.18c06c2.296
20...@aol.com>) about 'EMC-related safety issues', on Mon, 31 Dec 2001:
> Quite a number of EMC and Safety experts took part in creating the
IEE's
> Guide on EMC and Functional Safety, including a lawyer who specialises
in
> high-tech issues. You will find their names listed at the end of the
'core'
> of the guide (downloadable from www.iee.org.uk/Policy/Areas/Electro).
Many
> of these experts also involved their colleagues and others so we got a
very
> wide spread of opinion.
My comments referred to the IEC work, specifically verbal reports from
people involved. You will have noticed that the work culminated in a TS,
not a standard as originally envisaged. That in itself may be an
indication of certain difficulties in its passage through IEC.
I think that a passionate defence of the IEE document (which I have not
studied, so will not comment on) *may* also be an indication that there
is more emotion surrounding this subject than is desirable.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
After swimming across the Hellespont, I felt like a Hero.
