Safety PLC's

<h1>Safety PLC's</h1>Author: <a title="Mark Till" href="http://www.articlesbase.com/authors/mark-till/221104.htm">Mark Till</a> As the law changes on machine safety so will the design philosophy required to achieve a safe system. I recently attended a training course on safety PLC's and was initially shocked that we were moving away from traditional techniques. Over the years I have been involved in designing and commissioning many safety systems, some good some not so. So what will the new legislation mean to people like me, firstly forget the hard wired interlock? Yes that's right all the knowledge you have just forget. This took a while to sink in but once you think about it you can start to see the advantage - fault tolerance, previously we needed to add a lot of wiring and quite complex circuits to achieve fault tolerance and in most cases a fault would not be detected, it would require on a weekly/monthly safety check to ensure an out of position device would not reset. How often did these checks get carried out? By introducing a safety controller we can make the check happen and record the results! Wiring, when designing a circuit I would always wire back each E-Stop to the main panel MCC, this was often criticized, for the installation and wiring costs but at least the technician would have a starting point when trying to diagnose problem on a safety circuit. Often though this is not the case and one plant I recently worked on had over 60 E-Stops all wired in series, imagine a broken wire on that circuit. With safety PLC's this is no longer a problem as remote inputs and out puts can be used ensuring coded pulses prevent crossed channels and fault diagnosis can be fed straight back to the PLC we are no longer relaying on aux wiring the safety wire is now the feedback. So am I sold? Yes I guess I am and with correct implementation hopefully more robust systems can be implemented, that not only make plants more reliable but protect people. My only concern now is convincing a client.About the Author: Mark Till is a researcher for companies that run software based machinery and internet programmed applications. From web based
programming, designing and developing to industrial automation
<a href="http://www.ac-sys.co.uk/plc-programming.html">PLC programming</a>, Mark Till can recommend an experienced <a href="http://www.ac-sys.co.uk/">PLC Programmer</a> for all automation solutions.Article Source: <a href="http://www.articlesbase.com/">ArticlesBase.com</a> - <a href="http://www.articlesbase.com/programming-articles/safety-plcs-1169521.html" title="Safety PLC's">Safety PLC's</a>

As the law changes on machine safety so will the design philosophy required to achieve a safe system. I recently attended a training course on safety PLC's and was initially shocked that we were moving away from traditional techniques. Over the years I have been involved in designing and commissioning many safety systems, some good some not so.

So what will the new legislation mean to people like me, firstly forget the hard wired interlock? Yes that's right all the knowledge you have just forget. This took a while to sink in but once you think about it you can start to see the advantage - fault tolerance, previously we needed to add a lot of wiring and quite complex circuits to achieve fault tolerance and in most cases a fault would not be detected, it would require on a weekly/monthly safety check to ensure an out of position device would not reset. How often did these checks get carried out?

By introducing a safety controller we can make the check happen and record the results!

Wiring, when designing a circuit I would always wire back each E-Stop to the main panel MCC, this was often criticized, for the installation and wiring costs but at least the technician would have a starting point when trying to diagnose problem on a safety circuit. Often though this is not the case and one plant I recently worked on had over 60 E-Stops all wired in series, imagine a broken wire on that circuit. With safety PLC's this is no longer a problem as remote inputs and out puts can be used ensuring coded pulses prevent crossed channels and fault diagnosis can be fed straight back to the PLC we are no longer relaying on aux wiring the safety wire is now the feedback.

So am I sold? Yes I guess I am and with correct implementation hopefully more robust systems can be implemented, that not only make plants more reliable but protect people. My only concern now is convincing a client.

Mark Till is a researcher for companies that run software based machinery and internet programmed applications. From web based programming, designing and developing to industrial automation PLC programming, Mark Till can recommend an experienced PLC Programmer for all automation solutions.

Rate this Article:

0 / 5 stars - 0 vote(s)

Re-Publish

Article Source: http://www.articlesbase.com/programming-articles/safety-plcs-1169521.html

Article Tags: Plc Programming, Plc's, Plc Programmer

Related Articles
Related Q&A

1. Glenn Adams (19:57, 25.11.2009)

Can you elaborate on the law changes for safety relay systems vs safety PLC's

Latest Programming Articles
More from Mark Till

Integrating facebook in cakephp

By: Digisha Modi | 30/12/2009
FaceBook Application is the powerful tool of marketing or to connect people for all type of business. Now it's easier to find social applications on Facebook, on your phone, and on external websites. The new "Featured by Facebook" section highlights Facebook's favorites. Since 2007 the kind of concept FaceBook has come up with become a unique challenger to established payers. The benefit of FaceBook application is any one can post their own application with out any cost.

Outsourcing of iPhone Application Development Offers Profits for Developers as Well as Users

By: Arun Kumar | 30/12/2009
Being a 3G phone, it offers users the advantage of thrilling web access which helps them being on top of all online activities even on the move. Also, there are several additional applications available for download for the device. Thanks to the efforts of the outsource iPhone application development firms which have helped iPhone users get more with their devices using the apps developed by their expert developers.

Magento Template Integration

By: Digisha Modi | 30/12/2009
If you have purchased Magento template or simply need to integrate an existing graphic design template into your e-commerce shop we will integrate it into Magento for you. A web template is a ready- made web design need to be integrated. Usually web templates make possible a standardized layout (page arranging, colors, positions, etc.) for different web contents while using the same basic layout.

Magneto Template Designing

By: Digisha Modi | 30/12/2009
If you want your magento store to be very attractive and user friendly then we at Biztech Consultancy do it for you. We help in customizing the appearance of your Magento e-commerce store with Magneto’s powerful theming engine. Basically Magento theme is combination of layout, template and/or skin file(s) that create the visual experience of your store.

Pass4side 000-135 practice test

By: Adela1987 | 30/12/2009
Pass4side 000-135 Details: Pass4side is your source for the IT Exam 000-135 exam. With our 000-135 Exam Resources, you can be rest assured that you will Pass your 000-135 Exam on Your First Try. Our Exams are written and formatted by Top senior IT Professionals working in today is prospering companies and data centers. All of our practice exams including the IBM 000-135 exam guarantee you success on your First Try. 000-135 is a challenging exam,with our 000-135 study guide,you can feel safe wit

Open Source Development

By: Digisha Modi | 30/12/2009
Open Source Software are free applications released under special licensing terms where the core coding is viewable and able to be edited to suit the needs of the user. Open Source applications cover a myriad of uses - from entertainment to enterprise ecommerce. Open source software like Joomla, magento and osCommerce are very popular and widely used. They are content management system and it maintains track of every piece of content including music, videos, text, widgets, images and documents.

Cakephp PhpBB Integration

By: Digisha Modi | 29/12/2009
PhpBB Forum is a popular bulletin board script written in the server side scripting language PHP. Installable on most web servers, it is free open source Framework available under the GNU public license. The software allows website and forum administrators to set up unlimited number of forums and categories. It is also possible to create users, moderators and user groups with varying degrees of permissions.

Cakephp Amazon API Integration

By: Digisha Modi | 29/12/2009
The Amazon Web Service lets your cakephp web applications make queries to the huge database of products at Amazon and extract as much information as you need. The information you get in your application is exactly the same that is available on the Amazon website at that instant. The Amazon Web Service returns data in real-time, and updates automatically.

What Makes a Good PLC Program?

By: Mark Till | 27/08/2009 | Programming
PLC programmers have been faced with a steep learning curve over the last 25 years, as technologies have moved quickly and almost all industries have implemented programmable logic controllers as a standard. This means that good experienced programmers are hard to find, and while most companies offer programming services there are important features which are often missed out.

SCADA and HMI Applications

By: Mark Till | 27/08/2009 | Programming
Over the recent years there has been many developments in automation products, so much so that it can be considered that HMI's (human machine Interface) and SCADA's (supervisory Control and Data Aquistion) have become much the same. In the beginning a clear difference was created where HMI's we dedicated electronics that had the ability to communicate with other dedicated electronics.