PLC Program Problems

we purchased a oil filtration plant...from your good company

Whoa there!

CR4 does not supply anything. We're an engineering forum not a manufacturer.

You must have the wrong address.

Many PLCs have an energy storage device that maintains the PLC's memory in the event of a power interruption. The user manual will give change intervals for batteries. Has the simple preventative maintenance task of changing the battery for a fresh one at regular intervals actually been carried out?

I totally agree!

Check your battery...

Invitation declined.

Can you define which model and make of PLC you are using

You are right on. The generator that "guest" is using no doubt is less than a perfect source of power. The UPS's are a good idea, smooths out power and carries you through the switchovers. The only caveat is that they run on batteries and they will need to be replaced every couple of years. Many of the UPS's have monitoring software so you can check your supply voltage and check battery life and log power events.

Dear GUEST,

You seem to enjoy working anonymously. Come on! give your name and location - that simplifies lot of issues.

I am sorry, but I can make out that you are not able to understand the basics. You happen to be in a position which is probably forced on you, 'or' you have accepted due to compulsions and it is very clear that you are not enjoying it.

Any PLC will conk-off if power is interrupted and if its back-up (memory) battery is gone. This is especially true with certain branded old PLCs like S5 or S7. You end up loosing the whole program.

Just change the memory battery and get it reprogrammed once again.

It is a different issue that you have to ascertain how proper change-over from supply power-to-generator and vice-versa is affected.

It doesn't sound like this system is old enough to be losing the battery on the PLC. Most of the lithiums last so long now you forget about them being there unless you have them on a PM sheet.

If he is getting ugly spikes and transients on the line it will definately cause issues in the PLC.

As suggested above you can try an UPS...just put battery replacement on a regular PM annually. Also, I would stick in a 1:1 isolation xfmr. Do the normal clean power stuff. If still an issue go to a little sola or equiv DC supply and change out the PLC rack supply to run on DC.

Certainly, unless your warranty expressly forbids, your engineer ought to have a copy of the program and the software to deal with it.

I suppose all given advices won't deliver desired result. Simply your company deals with not good supplier. Either "good supplier" its turn had been supplied bad PLC decision.

As was said at forum --- EEPROM and NVRAM both are securing enough time span (for years) to be assured that all stored data won't be lost in any worst case. You've told that PLC loses config file. Be honest it's simply should be practically impossible event for certified PLC being designed for industrial application. Its might be suspended, some wrongdoing but even as though it loses config data it should restore default factory data. Though "should" or "would" just is not the same and depends of "developer's" conscience.

BTW to blame Power supply interrupts (or blackouts) is lovely excuse of any "bad" developer (though it is impossible notion as developer simply can't be bad).

There are a lot of program techniques to shun such casualties. WatchDog timer (when PLC reset itself compulsory), storing data in energy-independ memory and so on.

AND There are a lot of ways (unfortunately) even having used known brands like Siemens or Omron download there code full of not-fixed bugs which could play their bad role for memory write/read operations.

You said that had been experienced the same problems for other machine. It's bad sign and trend. So I think even a wagon of UPS' won't bring remedy.

Here there are whether bugs-full codding either bad designed architecture of PLC or both of ones. Concrete type of employed internal PLC power supply is significant as well.

If I were you, I would demand to fix this problem immediately. If needed a metric tone of ups to resolve bug. Your "good supplier" should deliver one for free.