AB PLC Firmware Updates Good or Evil?

I have been at many contractors and have heard from many programmers that updating firmware is a terrible idea.

Recently I ignored that. I had a control logix that was version 10. That means It was windows XP only for logix 5000 and now I can at least get to it on my windows 7 box.

I know you can brick a device if you lose coms. I connect directly to the PLC when doing this. It also erases the program and you have to convert it. Conversions warn you that things may break.

I invite you to tell me why. Should I never update firmware, or are people being ridiculous?

We won't do it to a running system w/out a good reason. Not being able to support v10 easily would be a good reason imo.

But we flash everything new to our 'standard' for that hardware. Just makes support easier to have things relatively consistent.

JeremyAdair87 said:

Should I never update firmware, or are people being ridiculous?

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Neither.

You should evaluate whether to update case-by-case. Moving up from a version as old as 10 is probably a good reason to do it, but it is always a good idea to evaluate the impacts of the later version on the actual application.

I tend to leave well enough alone with firmware unless there is a known bug or enhancement needed that will make money. If it don't pay, I won't play with it.

I recently found out that ab is storing comments in their PLCs now. It started around version 21 I think. Anyways I found out when complaining to a contractor That I needed my up to date tags and made myself look.. less than professional.

If I had been keeping things up to date I felt I would not being making out of date mistakes.


Thanks for the input. I will leave it alone.

If I had been keeping things up to date I felt I would not being making out of date mistakes.

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just keep in mind that each "family" of processors can only be flash upgraded to CERTAIN LIMITED firmware levels ...

anything running version 10 is definitely NOT going to be flashable up to version 21 ... so – going that high up is going to require a processor replacement ... I suggest that you be sitting down when you find out what that's going to cost ...

going a little further - with the original question ...

the yes or no answer can be different IF you are the "owner" of the system - or if you are a vendor/contractor who drops by the plant once in awhile for a service call ...

suppose that the plant has their own laptops happily running the "old" version - which are used for troubleshooting by the plant's maintenance crew ... if you (without proper planning) upgrade the firmware - then those other laptops won't work until their software is also upgraded ...

I know that the scenario described above is not your situation - but I thought that it might be worth mentioning for other readers who might have similar questions ... (you would not believe the horror stories that I hear in my day-to-day work) ...

finishing up ...

Thanks for the input. I will leave it alone.

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ah ... the old "if it ain't broke - don't fix it" rule ... always a wise choice ...

and have heard from many programmers that updating firmware is a terrible idea.

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sounds like the voice of experience speaking ... obviously these guys have been bitten by this particular dog before ...

TIP: you might want to look into a copy of VMware and run an XP virtual machine on your Windows 7 laptop ...

If it ain't broke....

I did see a job specification for a Control & Automation Engineer, with one of the roles specifically mentioned..

• Upgrade PLC firmware every 12-months.

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And I understand it is an Allen Bradley site, cos I remember them using PLC5 when I did a Technical Visitor Tour when I was enthusiastic.....

There are improvements to not only the firmware but the programming software itself; Studio 5k started storing comments on the controller at v21, then eventually got program parameters with v24 reducing the need for controller-scoped tags shared by all programs. This also makes event programming a little easier since you can write to program-scoped tags encapsulated by an event task. v30 has added the ability to do string processing with literals with a 5x80 processor and higher (I have some of our systems send emails on certain alarms so that comes easier than creating and maintaining a string tag for each message, I suppose).

Things advance and I prefer to know the *potential* of a system even if I don't use it right away.

Ran into a system not that long ago running V2 5000. When I contacted tech support to get the best method to update, the guy on the other end chuckled and said 'good luck'. I ended up installing a separate VM each for V2, & V9. Then from V9 made it to V10. Each jump had it's own issues of incompatible/obsolete/modified functions etc.

Moral of the story, don't fix it if it ain't broke, but jeez, don't wait forever and put your plant in a bad spot.

AGill said:

Moral of the story, don't fix it if it ain't broke, but jeez, don't wait forever and put your plant in a bad spot.

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That about sums it up for me. If I can't find a reason other than "it's not the latest", I tend to leave it alone. If I find myself wanting to do something that requires a firmware update, or would be made significantly easier with the latest version of firmware, or if I find myself having to do all sorts of tricks just to get online because the software version is so out of date, then I'll definitely entertain the idea. Of course, I'm a contractor, so as Ron suggested it's important for me to check out what else is going on around the place with the maintenance techs and engineers and what versions they're running. The last thing you want to do as an outside contractor is lock a site engineer out of his own PLC. That won't help your chances of winning the next project!

As a side note, regarding the PLC's storing their comments inside the PLC now. This only applies to certain models of hardware, as well as certain versions of Logix Designer. To store the comments, the PLC must have a dedicated physical memory area - without it, it doesn't matter what version of software/firmware you're running, the PLC physically can't store it. It's helpful that in most cases, hardware that's not capable of this only supports up to v20, and hardware that is capable of this only supports from v21 upward. So for the most part, you can equate the v21+ firmware with the ability to store comments - but I believe there are a couple of exceptions on the 1756 Control Logix range.