PLC program backup

I work with companies that are sloppy with their PLC programs. They assume nothing will happen and say they will save the files later.
But one of these companies does save the programs properly and also loads them into spare PLC's so they can just swap the CPU or brick unit when something happens. Here's my concern and question:
Do all PLC's have an eeprom type memory? I think some of the small brick type unit do not and the program will be lost once the battery goes. So I'm interested what you recommend clients in general and also if keeping a spare PLC on the shelf for years is recommended.

Not all PLC's have eeprom's it would depend on the brand nd model.
with Rockwell you can use RSLynx to back up the programs
if you set up Bootip and have it assign the IP address of the processors when yohave to replace the PLC just make sure that it assigns the correct IP address then down load the backup. there will be other options depending the PLC you are using.

I warned a company for years about backing up their programs.
They never did and wouldn't pay me to do so.

They were a bad company and only used me when they were desperate. Desperate = nobody else could fix it or do it.

I didn't work for them for years until a phone call. Their old Mitsubishi A series (20 years old at least) failed.
The battery had died and they had lost the program. They had another programmer in to verify this.

It had hundreds of I/O and the factory was at a standstill.

They were still cheeky though. They asked me if I still had a copy and would I email them it for their programmer on site to put it back in.

They expected this service to be free.

It wasn't free and I watched my bank account until the money was transferred before I sent them it.

They still said bad things to me and about me for holding them to ransom (as they saw it) Nothing about how I got them back in production within an hour and saved them $$$$$ in lost production and reprogramming.

ThomasGruetter said:

Do all PLC's have an eeprom type memory? I think some of the small brick type unit do not and the program will be lost once the battery goes. So I'm interested what you recommend clients in general and also if keeping a spare PLC on the shelf for years is recommended.

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Most newer and some older have them or have them available, if you let us know what models we can tell you, I just did one for a customer that wanted a spare 5/05 because they have one in a hot humid, dusty and lots of vibration... its going to fail again its just a matter of when, I put their program on the eeprom and wrote instructions on how to install the back up when needed.

Ronnie Sullivan said:

It wasn't free and I watched my bank account until the money was transferred before I sent them it.

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You did not take a check

Thank you all. The PLC I just programmed is a Twido (Schneider) - it is a brick style very basic PLC. It states that the battery keeps the program for 30 days. The battery cannot be replaced. This customer keeps many PLC's on the shelf to get back online quickly if something fails. Most of their PLC's are AB Micrologix and SLC500's and some Copmpact Logix. I thought maybe they should keep the spares under power but this seems a bit crazy...They keep the spares because they do not know how to load the programs themselves. So I see it as my responsibility to let them know that some PLC's could loose the program after the battery goes bad. At the same time I guess most PLC's use EEPROM's?

ThomasGruetter said:

The PLC I just programmed is a Twido (Schneider) - it is a brick style very basic PLC.

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I dont think they have eeproms and since (I think) they are no longer made I would upgrade it, they recommend a M221 and that does support a SD flash card

https://www.schneider-electric.us/en/product-range/533-twido---programmable-controller/

If all the other PLC's are AB you may want to recommend they replace it with a 1100 or 1400 they both have MM1's that you can store the program on

Their SLC's and CompactLogix should support the EEProm and depending on the MicroLogix they have if they do or dont

I've never seen or recommended keeping physical PLCs replacements powered on at all times, although I could see how this may be relevant to high availability systems. That being said, I'd probably just build a simple 2 PLC system where needed so that it can be swapped to in the field.

As far as backups go, I always go over the long term strategy with my clients and makes sure that at the very least they have all the files backed-up and labeled on a shared drive. If they don't have many people messing with those, it's an OK strategy. The step above would be to use Rockwell Asset Manager if they have a team of 5+ people & make sure that everything is backed up automatically.

NEVER forget about bubba!
he will go in there and make a change and it works for 1 cycle and he leaves. the next shift guy (me) has to deal with it. bubba never looked at what the sensor he removed from the program did else where (it reset the cycle sequence). thank GOD for program backups stored on the laptop!

good backups are a must! laptop 1 has the last plc change and you have laptop 5 with no idea of what has changed, so you assume the plc program is correct. lots of issues to deal with and debug.

james