L32E lost it's program - battery is okay and FRN is the latest version of 18

[brstilson]

Went out on a service call last night. The processor, a 1769-L32E, was faulted. It has 2 Spectrum universal analog input cards and a DC Ouput card. When I got online it said the PLC had no program in it, so I downloaded my backup copy. Then I had some issues with the IO. Wouldn't communicate with the Spectrum cards. What I THINK ultimately was the issue was the connection between the cards. You really have to push on those levers hard to get them to seat properly (which is a gripe I have about the compact series, but that's a different thread), but once I got everything seated right, everything worked again.

But why would the Processor lose its program to begin with? The battery is good (I'm getting no low battery light at least), and the equipment has been running for at least a week and a half before this. I looked on the TechConnect website and found a few notes about batteries (pretty sure it's okay), and something about a glitch in firmware 12 and 13 (this processor is at 18.22?, whatever the latest version of 18 is), but nothing else.

 

[Lancie1]

Another lost program report. It seems to be a repeating pattern but with different models of processor.

 

[dmargineau]

...definitely an "insufficient evidence to admit it" bug...

 

[schui]

I had the same problem on a L32E that went on for ages, I changed CPU, Power Supply, External Power Supply what I found eventually was that the air filters on the doors were clogging up and not enough cool air inside the panel, so we started to clean them every week and to this day 1 year or so on It has never went down since, I could never find a way of monitoring the temperature in the CPU

 

[dmroeder]

Are you sure you are on 18.22? I looked up firmware updates for L32E's and the latest as far as I could tell is 18.12.

Anyway, in the 18.11 release notes I found this:

[FONT=&quot]After clearing a fault due to a missing I/O modules and cycling power to the CompactLogix controller, the program is lost from controller memory and no fault is logged.[/FONT]
[FONT=&quot]With firmware revision 18.11, cycling power after clearing a fault for missing I/O modules does not result in the program being lost from controller memory.[/FONT]

 

[brstilson]

Are you sure you are on 18.22? I looked up firmware updates for L32E's and the latest as far as I could tell is 18.12.

Anyway, in the 18.11 release notes I found this:

I don't remember the exact number, but I told the TechConnect person what it was and he told me it was the latest version.

 

[brstilson]

I had the same problem on a L32E that went on for ages, I changed CPU, Power Supply, External Power Supply what I found eventually was that the air filters on the doors were clogging up and not enough cool air inside the panel, so we started to clean them every week and to this day 1 year or so on It has never went down since, I could never find a way of monitoring the temperature in the CPU

You might be on to something. This panel is close to a press that heats dies up to 1750 F. There is a cooling fan in the panel, plus the die holders are liquid cooled so the heat doesn't transfer, but it still gets fairly hot up close to that area. Problem is, the PLC ran fine for a few years and this only happened after we added a module to it.

 

[jdbrandt]

You might be on to something. This panel is close to a press that heats dies up to 1750 F. There is a cooling fan in the panel, plus the die holders are liquid cooled so the heat doesn't transfer, but it still gets fairly hot up close to that area. Problem is, the PLC ran fine for a few years and this only happened after we added a module to it.

Key piece of evidence.

Remember that in 1769 the power supply rating (say: 2 amps) means, really, 1 amp per side of the power supply.
If you added a module, you very likely added it to the rightmost area...and THAT may have broken the 1 amp per side rule. I've seen this rule broken, and the PLC would run....and then die at some random time afterward.
Run your calcs, and make sure the power supply is not overloaded on either side. You may have to shift it to the right to shed load on the right side (assuming you don't overload it on the left.)
Good Luck.