HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Page 1/2  >  >>
Rob Spiegel
User Rank
Blogger
Re: But are the functions really separate?
Rob Spiegel   1/29/2014 2:10:26 PM
NO RATINGS
William K, it should certainly be interesting. Thanks for the idea.

William K.
User Rank
Platinum
Re: But are the functions really separate?
William K.   1/29/2014 2:03:04 PM
NO RATINGS
Rob, I am certain that it will gather a lot of attention and interest quite a few folks. Safety goes way beyond just being safe, it also seems to require that industrial equipment, at least, be guarded against those who are way beyond just incompetent. 

So it will be very interesting to see what some of the manufacturers, such as Siemens, have to say about thier safety systems.

Rob Spiegel
User Rank
Blogger
Re: But are the functions really separate?
Rob Spiegel   1/29/2014 6:25:36 AM
NO RATINGS
Well, Willliam K, perhaps the next step in our conversation on this subject is for me to go out and see what people are asying about this. So I'll do the story.

William K.
User Rank
Platinum
Re: But are the functions really separate?
William K.   1/28/2014 4:26:53 PM
NO RATINGS
Ten years is probably a long enough time for that constantly repeated assertion to have taken on an " aura of correctness", no matter what. But all of those mechanisms for keeping the systems independant should be covered by patents now and so be something that can be discussed with the engineering community. And I am one who would really like to hear how a hardware fault in a processor only affects part of that processor. Of course, over the years, I have come across digital ICs that had partly failed, but not very many of them.

Rob Spiegel
User Rank
Blogger
Re: But are the functions really separate?
Rob Spiegel   1/28/2014 11:47:24 AM
NO RATINGS
Good point, WilliamK. The hype has been universal. It's been years since I have heard anyone argue for separate networks for control and safety. When I first covered this subject 10 years ago, the majority of plant operators I spoke with wanted separation. Now I don't hear anyone say that.

William K.
User Rank
Platinum
Re: But are the functions really separate?
William K.   1/27/2014 3:37:36 PM
NO RATINGS
Thanks, that is why I suggested it. Probably quite a few engineers would want to see what the reality is, aside from the hype. How are those two functions kept independant and yet in the same box.

Rob Spiegel
User Rank
Blogger
Re: But are the functions really separate?
Rob Spiegel   1/27/2014 10:26:45 AM
NO RATINGS
That's a great article idea, William K. I'll look into that.

William K.
User Rank
Platinum
Re: But are the functions really separate?
William K.   1/26/2014 4:48:28 PM
NO RATINGS
I am certain that some of the potential failure modes have been avoided on the safety section of the all-in-one-system PLC packages, but short of being truly triple redundant it is not reasonable to anticipate that they are 100% safe. And it would be very worthwhile to read the actual user documentation and see what disclaimers and warnings are there that don't make it to the advertising areas. 

In short, when a set of claims are simply too good to be true, I usually doubt that they are true. That attitude has saved me from a couple of disasters over the years. 

taimoortariq
User Rank
Gold
Re: But are the functions really separate?
taimoortariq   1/25/2014 11:00:17 PM
NO RATINGS
William, I understand your point. But I am sure that they must have done alot of rigourous experiments to check and finally verify the device, as SAFE. I mean I dont exactly know the internal architecture of the PLC security module, but if they are selling the product all around the world, they must have made it very robust under the fail conditions. Obviously, no system is 100% fool proof, but when they say that relatively this system is more reliable and safe then the other one. Than they must have made it more safer.

taimoortariq
User Rank
Gold
making lives easy
taimoortariq   1/25/2014 10:46:35 PM
NO RATINGS
Nice Article Rob, Smarter PLC's certainly makes lives much easier. To get stuck with the setup and configuration problems can be quite time consuming and equally frustrating. To have every thing combined in one PLC is a treat for a control engineer.

Page 1/2  >  >>


Partner Zone
Latest Analysis
Factory floor engineers may soon be able to operate machinery and monitor equipment status simply by tapping their eyeglasses.
GE Aviation not only plans to use 3D printing to mass-produce metal parts for its LEAP jet engine, but it's also developing a separate technology for 3D-printing metal parts used in its other engines.
In this TED presentation, Wayne Cotter, a computer engineer turned standup comic, explains why engineers are natural comedians.
IBM's new SyNAPSE chip makes it possible for computers to both memorize and compute simultaneously.
The “Space Kid,” 11, will be one of the first civilians to have his design manufactured in space by NASA, thanks to the City X Project, which inspires kids to think about new 3D-printed inventions that could be useful for humans living in space.
More:Blogs|News
Design News Webinar Series
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Sep 22 - 26, MCU Software Development – A Step-by-Step Guide (Using a Real Eval Board)
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: September 30 - October 2
Sponsored by Altera
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service