Ladder Logic or IEC6131-3

[Fitzroy]

Hi,
as a newcomer to PLC I am looking for a suitable Programming language to take up which will not go out of style in the years to come . Could you help me decide between Ladder Logic & this so called new language IEC 61131-3 ?

This is an exstract from a company selling courses in IEC 61131-3 is it true or missleading ?

'The international standard, IEC 61131-3, published in 1992, provides the open standard for programming of a wide range of industrial control systems in a universal, vendor-independent way. The majority of PLC systems are now programmed using IEC 61131-3 languages.'

thanks Fitzroy

 

[Steve Bailey]

If you search the archives of this forum, you will find plenty of discussion on the topic.

The IEC 61131-3 specification is not a new language. It is a definition of five distinct languages for automation programming, one of which is relay ladder logic. An automation controller may employ any or all of them.

What it definitely does not do is guarantee that a program written for one brand or model of PLC can be run on a different brand or model, even though both models may claim IEC 61131-3 compliance.

 

[jvdcande]

I am looking for a suitable Programming language to take up which will not go out of style in the years to come .

Fitzroy,

since all PLC programming software is manufacturer dependent, it's very difficult to tell you what you need. Although some brands are better than others from this point of view (Siemens has changed the user interface of STEP7 with almost every new version, while RSLogix5000 hasn't over the last 4 versions I've seen), this is a poor definition of what you need. What you need is the software for the brand of PLC you'll be using. Thus better questions are:

• What type of PLC will I be using over the next couple of years?
• What type does generate a need for programmers in my area?
• What type is used where I live?

For my region (Flanders) I would say go to Siemens, it's the most used over here. Choose the S7, because it's their new family and S5 is fading out. Unfortunately, it's the one which changes it's user interface most often.

Kind regards,

 

[jvdcande]

Oh yeah, what I forgot to tell:

IEC61131-3 is only about what you see once the program is written, it tells almost nothing at all about the programming software.

In other words: if you see a listing of a IEC 61131-3 compliant program, there's a big chance you will understand it. There's no guarantee at all you'll be able to program that kind of PLC until you've learned to use the programming software package.

On the other hand: (almost) everybody is able to learn. As a trainer I know what I talking about .

Kind regards,