compact logix losing program

I was called out at freaking 2:00am tonight to go over to a customers plant here in town. I get there and they said it was just running and stopped, The piece of equipment is a box former with a compact logix plc connected to a TCP touchscreen. Anyway I get there and the touchscreen is displaying PLC com error, so I reload the program to touchscreen via memory card still not working. I grab my laptop and try to go online and I get "no project currently in the controller" I download the program and whoalaaa its all better. I was thinking maybe the battery backup was bad so I cycled power to see if it retained the program and it did. Has anyone experienced this before. I normally supply a line filter with all of the panels I design but I didn't put one in here for some odd reason. Could not having one have done this? any help appreciated

I dont think there is any connction between line filter to the backup battery.
You might have defective battery or shortcut which cause the battery to drain down.

According to A-B, they have this feature to insure safe operation in all PLC5 and Logix processors:

If firmware detected that it is not safe to keep current program, it will erase it and in most of case create log file to tell you what happened.

Most common problem it a memory parity error caused by noise or power surge, but also it is possible that processor came to a point "of no return" during program execution.

To extract fault log call techsupport with your valid contract number and they will give you extraction utility.

I started a thread on Rockwells forum about this very topic.

Yes, upon a major fault the program is cleared !

It should be possible to set up the program to be loaded from the CF card, in case this happens again.

I have heard of three cases where Controllogix processors randomly lose their program just like what you described in the Compactlogix. I don't use the CLX platform but I am trying to decide whether or not to spec one for an upcoming project. I have spoken to another PLCs.net member,tz12fh, who works with the CLX platform and has never seen the problem. There is the thread that jpers mentioned and it mentions the Compactlogix. Structuring the programs carefully seems to be the advice that is given as well as firmware and Logix5000 versions. My personal feeling is that the flagship product of a company like AB should be solid and have these type issues ironed out before they are put out on the market with the price tags that they carry. but that's just me.
smiller

JesperMP said:

Yes, upon a major fault the program is cleared !

Click to expand...

Jesper - how is a "major fault" defined? That doesn't strike me as the most reliable way to "safeguard" a control system. I can live with the "checksum / invalid ram" fault clearing the program, but other than that . . .

I found out of this while skimming through the manuals and release notes for the Compactlogix. I actually do not use CompactLogix at the moment. I was thinking about it, but have decided to wait "just a little longer" until all the little issues are ironed out.

I started a thread on Rockwells forum, and it confirmed that it really is true.

How to define a Major Fault on CompactLogix I do not know.

It looks like this 'clearing of the program' is a part of every AB processors last-ditch safety procedure - even PLC5 and SLC500.
But according to the feedback on this and the other forum, I would say that CompactLogix is more likely to perform this harakiri than the other AB processors.

And I was looking into using this stuff!!!!!

So a system sent a continent away may loose its program upon noise triggering am error?

Is that so?

Then would the 5/03 be more appropriate?

pierre.

It should be possible to set up the program so that it loads from the CF card when this happens.

If it is possible to somehow store an error code so you have an idea what caused the error I dont know, I would guess that it is possible, but it is not easy to find anything about this in the manuals. Maybe someone who knows will care to elaborate.

Your worry about sending the thing abroad is exactly what worries me as well.

Imagine JesperMP when we connect with a modem, and with all the communication difficulties when dealing with telecom system, anaolog line, pbx and transfers.

There is enough challenge here not to have to worry about messing it up to a point where we loose the communication because we lost the program.

I face program missing quite a number of times in the PLC (mostly SLC) in my country, most of them we suspect due to lightning strike. Not much CLX or CompactLogix install base here yet