craisondigital

Best Practices (Standard Operating Procedures) CompactLogix & PanelView

13 posts in this topic

We've purchased an Autoclave at auction with CompactLogix L32e and PanelView Plus 1000.  With the help of some forum members and a local engineering company we have the machine finally working!

I'm looking for some advise as to how to train users for standerd operation.  For example:  Their is a toggle switch on the front which powers on everything (PanelView, processer, switch, etc).  We close at 5pm each night.. Should we Power down the machine each night, or leave it on? Another user mentioned a battery and I was a bit confused with the manual. With the machine off, Is the PLC only holding the program because of the battery??

I have backups of the following.. (.acd, .apa, .mer) files.  I also have created a Disc Image of the Internal Flash card on the PanelView.  Is their anything else I should have a backup of?

Their is a CF card in the PLC.  It has a folder called "Logix" and one called "System Volume Information"  In the Logix folder is  a CurrentApp folder with a .bin and .p5k file.  Does anyone know what exactly these are doing??

Any other advise is greatly appreciated.  Thanks so much for your time.

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You may get quite a few different answers to this question.

Personally, I don't like to turn the PLC off unless it's for specific maintenance and even then I don't like to turn it off. The battery has a finite lifespan. If I remember right we change our batteries once every 3 years. I also put a Battery Fault Alarm in each program in case a battery dies before we catch it. If you power the PLC off then the only thing holding the memory up is the battery. I wouldn't trust that..

If it's set up for to do so the PLC can retrieve the latest saved image from the CF card. However, if an edit is made to the program and it isn't backed up to the CF card it will load the old version over the new program IF it's set up to do that. There are various options for when and how the backup is loaded. I stopped using the CF card since the process of backing up required a system shutdown. If the PLC "loses it's mind" a tech has to either remote in or go to the site and download the program to the PLC.

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Thank you. So to confirm, the PanelView holds its program on the internal CF card and does not require power to store this.

the PLC stores its program to memory which is wiped clean if power is lost to the PLC.

also, I can reload the program to the panelview using the external CF flash card (no software needed), but can only load the program to the PLC if I have the software, or if it is somehow setup to look for a program on the ext. CF flash slot of PLC.

Edited by craisondigital
Added info

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Also, one thing strange is that the unit sat in a warehouse w/o power for 7 years before we bought it, but the program was still loaded on the PLC when we fired it up. 

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If i understand correctly, the PLC Flash card has the program stored on it.  So it wouldn't matter if the battery died during the 7 year power off.  As soon as it powers up, it will load the program that was stored on the card.

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The PLC requires power to keep the program in memory. This is supplied by the input power when it is on and by the battery when the input power is not on. There are some capacitors that will give you a few minutes if you lose power and don't have a battery. It's not impossible for the battery to hold out for 7 years if it was fresh, but I'd definitely recommend replacing it with a new battery at this point. As long as you are diligent about replacing the batteries periodically, you'll be fine to turn the system off at night. The PLC supports a CompactFlash card that can be used as non-volatile memory to store a copy of the program to be loaded under one of three circumstances: 1) manually using RS Logix, 2) on CPU error (lost program), or 3) every time the CPU powers up. As Michael mentioned, every time you change the program you have to remember to also reload the nonvolatile storage, which requires stopping the PLC, so I also avoid using this method preferring to just maintain copies of the program on a computer. This will be the ACD file you have. Also be aware that data memory (i.e. machine settings, recipe values, etc.) are stored as part of the program. This means that you definitely don't want the non-volatile memory reloading the program every morning, as it will overwrite any data changes made the day before. Loading the program requires the software. Other than the non-volatile option, this is the only way to do it.

The Panelview memory is non-volatile already, so nothing really to be done there. I don't bother copying the internal flash memory of the Panelview. The MER (runtime) file and the APA (project archive) are all you should need. The runtime can be loaded onto the Panelview using a CompactFlash card or USB flash drive without needing software in case of a failure, and the APA is the preferred method of archiving the project. These days the runtime can be decompiled fairly painlessly, so that's all that's really necessary, but I usually like to keep the archive as well.

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Ok, thanks. So based on that info I am assuming that our PLC is not using the CF because we lost the program somehow when a tech removed the I/O module with the machine running and had to have someone with the software out to restore it. He restored it using my backup files so I know those are all good.

Is it safe/recommend to replace the battery with the machine on.

i don't have the software so don't want to lose the program from the PLC when replacing the battery

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yes

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Safe, but not necessarily practical. The battery is under the left endcap on the processor. Depending on how the PLC is mounted in the panel, you might need to take out the processor to access the battery. That's why the capacitors give you a couple minutes, so you can change the battery without losing the program.

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Just a point to add that I don't see mentioned here. These batteries do not recharge. Once they're dead they stay that way. 

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Huh, I never noticed that before. I always assumed they were rechargeable, since they are lithium. Good to know!

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They are not rechargeable and they are also much more expensive than the average battery.  Which is another reason to minimize the time the PLC spends powered off.

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Thanks for the info everyone. I've ordered a new battery and am leaving the machine on until I can change it.

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