CompactLogix losing program??

Hello,



I got called in last night on a machine that has a CompactLogix L30ER running that suddenly went into "Recoverable FAult" with the OK light blinking red.

After switching the key switch to PROG and back to RUN, the program didn't seem to do much and when I went online with the PLC it said that it didn't have any program in it.

Loading the program solved the issue, but I'm left wondering why something like this would happen out of the blue on a machine that's been there for years now.

Anyone has had experience with this happening to them? I'm not the most knowledgeable in Rockwell kit, but this seems a bit odd that would happen without a power spike or anything like that.

We have several compactlogix, controllogix and guardlogix safety controllers here at our location but I have never experienced what you are describing with them. However, we did have a micrologix 1400 that would randomly loose the program for no reason. The people at Rockwell were stumped and suggested replacing the unit. We did, and that was the end of it.

I've seen some old posts mentioning it happen, but not enough to think it's a common issue. It's just strange and I'm wondering whether it's a sign of things to come (sadly, no one on site thought of standardizing controllers)...

DarrylR said:

However, we did have a micrologix 1400 that would randomly loose the program for no reason.

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Brand new straight out of the box had one Tuesday, when I first power it up the screen was blank and the fault light was flashing, I rebooted and the screen came back on but the fault was flashing, now I can load a program and it works great but once I disconnect the power it will fault out, I may use a memory card to see if that helps but I cant use it or sell it, this was the first time its ever happened... I did have one customer put 24vdc to a 120 CPU and he said it did not run right, but once I pointed out the issue it ran great

cardosocea said:

After switching the key switch to PROG and back to RUN, the program didn't seem to do much and when I went online with the PLC it said that it didn't have any program in it.

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I have never had the issue with a compact but you can load from the flash on a reboot and that may help it next time

Frequent weird problems like this have been solved by putting a line power conditioner going to the PLC power supply.

Dirty power can do wondrously bad things to electronics.

If this was a rack system (ControlLogix or SLC, or even S7) I would first replace the power supply and add a line conditioner. With a CompactLogix it is either a line conditioner or replace the whole thing if the power supply is going bad.

I know from AB inside guys there is a issue with power cycling the L36 that will cause a similar issue (program loss) but do not now if that covers the L30 as well. I have also heard that you can try to unlatch a specific bit in a routine and it will also cause the program to wipe (he wouldn't tell me which bit)