Converting a program from RSLogix 5 to RSLogix 5000

[hboyer90 3]

Hello, we are going to be upgrading the PLCs on some of our machines, we are currently using PLC 5 which run RSLogix 5 and we will be switching to CompactLogix that run RSLogix 5000. I'm wondering how do I convert a project/all of our tags from 5 to 5000? Is this a fairly simple process? Some of our programs are quiet long. Thanks for any help. Howard

[jstolaruk 9]

Start off by reading this: http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm085_-en-p.pdf

[rdrast 3]

I strongly suggest re-thinking the conversion. You would be much better served just re-keying the thing, and taking advantage of the Logix architechture. Take the extra time, it is well worth it in the end.

[hboyer90 3]

Could you expand what you mean a little bit please? Are you suggesting that we stick with the old PLC-5's or when you say conversion are you referring to converting the program from RSLogix5 to RSLogix5000? Why do you think the conversion is a bad idea? Is it just sloppy? And when you say re-keying you mean just re-writing the program out by hand? Thanks, just want to make sure that I understand what you're saying. Edited 11 Mar 2015 by hboyer90

[ASForrest 12]

I can't speak for rdrast, obviously, but my thinking would be the same as his appears to be. I'm definitely not suggesting you stick with the PLC-5's. But doing a straight "conversion" doesn't take advantage of all the benefits of the RSLogix5000 platform, like tag based addressing, UDT's, AOI's, etc etc. So yes, if I were you, I'd be sitting down in a quiet corner and going through the PLC-5 code in detail, work out what each section is achieving, and then actually write new code to replace it, rather than just import it into the new platform as-is. As rdrast said, I think in the long term it would be highly worth it. I've come across Compact/Control Logix PLC's that have been just converted and left (and even in some cases, brand new Compact Logix PLC's programmed as if they were a PLC-5 or SLC: "where's my N7 register? Never mind, I'll make my own. New tag: N7, type INT[100]. Done. Comments? Nah!") and given the potential of the platform it's woefully cumbersome.

[hboyer90 3]

Right on, I'm thinking that I'm going to have to do this anyways seeing as our configuration has totally changed now anyways. Thanks!

[kaiser_will 65]

Keep in mind that PLC-5's are completely different than Logix platforms. PLC-5 and SLC-500 and Micrologix1200 are I/O based PLCs, whereas Control and CompactLogix PLCs are tag-based. Additionally, the Compact and ControlLogix PLCs execute faster and differently than PLC-5. You are sure to run into issues in which the old program was slow enough to execute but the new program will probably have operational gaps where nothing happens because the old code was slow enough. If you have a huge, complicated PLC-5 project, converting to Logix is not a simple conversion. I have implemented a number of conversions and address the task much like a new machine program design. If you have a lot of remote I/O, you may be dealing with converting those racks also. I would suggest first working with your Rockwell sales engineer. Pull out the machine electrical schematics and understand the functions of what you have and features you need on the conversion, such as high-speed loops, servo motion, etc. If you have servo controllers, you likely will have to convert to newer stand-alone (Kinetix 350) or rack (Kinetix 5500, etc.) servo controllers.

[jstolaruk 9]

I've done it both ways and its usually the customer driving which we go. The last time, the machine was running production; we had weekends to test out the conversion, the electricians were used to PLC5s and SLCs, and the customer only had so much budgeted. So, their program has tags that simulate the file structure of a PLC5 and the logic mimiced the original program. A couple of times before that, the whole machine was being re-conditioned. It wasn't going to be used till sometime in the future, and a new machine would have been too expensive so the budget was more relaxed. They got a redesigned program with all of the bells and whistles. Edited 14 Mar 2015 by jstolaruk

[hboyer90 3]

So what I'm getting from all of this is that there is no magical tool that will convert everything from RSLogix5 to RSLogix5000 and seamlessly without any problems? This will be a learning experience for me that I am excited to tackle. Even if we have to re-write the whole program, I'm ok with that because it will give me a good chance to really learn the machine and all of it's components. In simple terms, what is the difference between "I/O based PLCs vs Tag based PLCs"? Sorry if that is a dumb question. Thanks.

[AndrewG 13]

In RSLogix 5000 (used for ControlLogix and CompactLogix PLC's) you create "tags". For example say you want to store a value that stands for a time delay. You can create a tag named Time_Delay_1. In RSLogix 5 (used for PLC 5) and RSLogix 500 (used for SLC PLC's) you do not create tags like this. Let's say, like in my example above, you want to store a value that stands for a time delay. You will end up using something like "N7:1" to store your integer time delay value. You can see how converting between RSLogix 5 and 5000 can get confusing. Sure you can create an RSLogix5000 tag named "N71" or something, but you may want to think about rewriting the program.

[hboyer90 3]

Alright, I gotcha. Thanks.

[rdrast 3]

Just re-create the program rung by run, but taking advantage of the new platform. Use tags, Use the newer instructions if appropriate, organize things differently, do NOT copy over simulated B, F, N file arrays. There is a conversion tool, it isn't 100%, and it generates truly ugly code. I try it every couple of years just to have a laugh. If I had a customer I didn't like though, I'd probably just go ahead, use the conversion tool, and deliver the goods. With any luck, they'd stop calling me. If the electricians can't get used to something new, they can keep their hands off. Things change. Programming for the electrician is idiotic. In a well designed system, there is no need for them to ever open the PLC code. Show faults and open interlocks and such on an HMI.