Posted 30 Jul 2013 I have two different machines that have failed me in the last couple of years. They are Compact Logix based, 1769-L32E CPU. The manual specifically says if the battery is OK and able to retain the program that the BATT LED on the face will be off. Every time we have checked on the PLC the BATT LED is off. If you unplug the battery or it is more than 95% depleted the LED will be red. I have unplugged the battery before and have verified that part to be true. However a few times a year a safety conditon will trip the whole electrical panel, turning off the PLC power. It SEEMS like with a fresh battery it is able to power back up but as the year progresses, if we are pushing a year or so, the next time we loose power we loose the program. We will find the panel powers back up in the RUN mode and all of the HMI displays are showing ???? (as in communicating but address not found) because when I get the laptop out I find there is no program in memory. To sum it up, the battery seems to work for awhile then fails. OK, that part makes sense but the BATT LED is not working correctly leading us to believe that there could be something else wrong? Also, we have resorted to buying a compact flash card and storing the program on the card. It is set to load on memory corruption only. This is also fine but not ideal. If we make any recipe changes then I have to remember to store the program again to the CF card. No big deal but I'm human and can forget - or not even know because I don't make the recipe changes. If the Engineer that logs in and makes recipe changes and he forgets to tell me we could be in trouble in a power failure situation. Say the battery is not going to work, and we power down and it restores an older program off the CF card. We will run and nobody will know we are running the wrong chemical times. It would be better to loose the program and make sure you put a good one in at that point. Of course the last time we lost a program before the CF card was installed, it was on weekend production and I was at home. As you can tell, there a few things I am considering here. Also, is there a way once a month that I can program an automatic backup to the card? Write just the recipe addresses to the card so it doesn't have to go to program mode to do a store or something helpful for my situation? This idea is not perfect or elegant but minimizes the risk of keeping a progam in non-volatile meomory that is not up to date. Any ideas? I'm not sure why these batteries are failing me and I'm not sure what I want to do next to eliminate this problem. Share this post Link to post Share on other sites
Posted 5 Apr 2016 Hello. Were you able to resolve this issue? I have recently had a similar problem at seperate locations. I have found some firmware related anomalies that could cause the problem. Share this post Link to post Share on other sites
Posted 6 Apr 2016 If you have a PLC battery, a regular Preventative Maintenance (PM) work order needs to be scheduled to service this battery. Period. Manufacturers will state expected shelf life; machine builders typically state this in their suggested maintenance section; end users should schedule the PM procedure into their work load. Along the same lines, if the best fail-safe method to control your program is to insure the program is manually backed up to the CF card, then this procedure should also be scheduled into a regular PM. Most of us have recurring meetings plugged into our Microsoft Outlook; this can be done for machine PMs (if one does not have access to a PM scheduling software package). Many lithium batteries suffer from "memory", in that the battery always charges to a maximum slightly less than it previously did. Eventually the battery is charging up slightly above its discharged value and boom, lights out, short time later battery is depleted. A-B notes " Check the battery indicator on the front of your processor and the installation date written on the battery cover and change promptly if needed ". Share this post Link to post Share on other sites
Posted 6 Apr 2016 I will second IndeckTech's statement. We had problems with the processors losing their programs w/o notice even with good batteries. It was firmware related. If I recall correctly, there was even a KB article on A-B's website about it. It was some time ago that I had the problem. The firmware levels involved were 15 and 16 and the KB article numbers are 45709 & 38430. There was another issue relating to the type of memory that was used on the device, but I think that problem was with communication cards, and not the processors. Kaiser_will is also correct when he states that a good PM system must be in place to replace old batteries. In the case of the problems we had, the batteries were only a couple of weeks old when we were losing programs. This is what led me to find another cause. Please let us know your resolution. Cheers. Share this post Link to post Share on other sites
Posted 2 Jan 2019 I also have a problem with the 1769-L32E, Compact Logix 5332E. This processor keeps losing the time of day. It is on 24/7, 365, and has a new battery, but still, randomly, loses the time of day. Could this also be a firmware issue? Share this post Link to post Share on other sites
Posted 3 Jan 2019 This rings 'a bell', it might be worth checking the tech notes, what firmware revision are you using? Share this post Link to post Share on other sites
Posted 3 Jan 2019 What is your firmware version? There is a known anomaly with v20: https://rockwellautomation.custhelp.com/app/answers/detail/a_id/970018/page/2 Access level: Everyone Share this post Link to post Share on other sites
