Software portability - IEC61131-3

[pascal01]

Hello to all!

I am a student of electrotechnics and automation. I have nearly reached the goal and have to do my diploma-thesis.

I have to watch out different PLC-Platforms and to check the portability of source-code between them.

The main tasks are to create some Function-Blocks (FB) in structured text (ST) and to check the possibility of their portability to an other (manufacturer independend) platforms.

Is here somebody who can help me how to find a good way to do that. Does anybody know the format *.fxf (standardised by www.plcopen.org) to exchange source-codes between platforms.

Thanks for any help

 

[pascal01]

experience on portability

... or is somebody here, who has experience on creating portable software???

 

[parky]

Hmmm... I have never actually tried to port one iec to another but I think you might have to do some work, it will depend on how the original program was written, I can see many problems with addressing, instructions etc.

 

[pascal01]

Maybe sombody else can help me???

Thanks for all help

 

[OZEE]

I truly doubt you're gonna get something that portable... there are too many proprietary differences between brands.

The standard (IEC61131) only tells them that they have to do certain things, not HOW to do them.

 

[L D[AR2P#0.0]]

pascal01 - I've ported code to/from Siemens SCL to Beckhoff structured text. It was a while ago now but the only editing required was the end of line character or something like that. I used copy/paste of text between the two editors. I also recall that Siemens STL will not easily port to instruction list.

 

[mellis]

The software they talk about on plcopen.org is something I've never actually seen in industry. For an organization that's been around 15 years, they haven't made much of a dent in this area. Everyone I know uses the manufacturer's proprietary software to program their PLCs. For ladder there is pretty much zero portability between brands. For STL, I would expect the cut-and-paste style of portability would work much better.

 

[pascal01]

yes, I already remarked, that the work PLCopen has done until now is not too much. :-(

Until now I already now see that the only way to create portable sofware will be to create all functions, FB's a.s.o. in ST and to work with copy/paste functions (Thanks to Bill G.... ! ;-)

I do my diploma thesis for a company offering turn key industry installations. And they are building up an automation department which will be in charge to supply the automation solutions for the installations and to create a more or less portable library of from object oriented to equipment oriented FB's.

And my task is to find out the different ways to do this, ..., lets see, ...

Thanks for your comments and for further comments

Greetings from Luxembourg

 

[TamHo]

Every PLC manufacturer has their own instruction sets, although they might have the same function, a latch/unlatch is the same as a set/reset bit.

Likewise, within your function block, certain instructions may differ slightly even though they have the same function. If you try to export it from PLC-X and import it into PLC-Y, the instruction may not be recognized and therefore will not work.

The good news is, once you've imported your function block from X to Y, a little bit of modification will make it reusable. If you only used the IEC 61131-3 instruction set for your function block, you should be ok but if you've used a proprietary instruction, you will have to modify it in order to work.

 

[pascal01]

@tam

thats what I am trying. to build function blocks on base of IEC61131 instructions.

And if it is done for equipment which is always build in the same manner, it should be interesting.

If somebody has good refernce-books or reports or anything else concerning the problem, thanks to inform me.

 

[JesperMP]

The graphically based IEC programming languages (LD-FBD-SFC) cannot be ported between PLCs. This because the way the graphical information is created and stored is different from platform to platform. "porting" means reentering the code in the respective editor.
Maybe tht .fxf format can change this. I didnt hear about that one before now.

The text baded IEC programming languages (IL-ST) can be ported between PLCs. This because the code is plain ascii text. As a minimum you can copy-paste from one editor to the other.

The software they talk about on plcopen.org is something I've never actually seen in industry. For an organization that's been around 15 years, they haven't made much of a dent in this area.

All AB controllogix languages should conform to IEC61131-3. In Siemens S7, the SCL and GRAPH language is the same as IEC61131-3 ST and SFC. CoDeSys is 100% IEC61131-3 (and thus Beckhoff Twincat and others also conform to IEC61131-3).

I think that when new PLCs appear in the market, or when an established brand brings a new generation to market, then there is a good chance that it will be IEC61131-3 compatible. To my opinion IEC61131-3 is slowly winning.

 

[JesperMP]

Out of curiosity:

Is the ST on the AB PLC5 platform compatible with IEC61131-3 ST ?