5/05 memory module - lost edits on power outage, how do I prevent this?

[bawaller]

Hello,
A few years back I was having a SLC 5/05 hard faulting, losing program, and requiring a download to get going again. The processor was replaced, but at some point in the process, an AB sales guy helped me install a memory module. Actually he didn't help me, he did it, I was there.

I do remember we set a few bits in the program for the MM to do it's job. Looking at the file now, I see the following bits are set:

S:5/8 MM Loaded on Boot
S:1/12 Load MM and Run

I think those were the only ones we changed, but don't recall.

We recently had a power outage, and a few days later I noticed some of my recent edits had completely disappeared, and user set points had changed. I'm thinking the memory module loaded the program as it was told by S:5/8. When I open the most recent file, with edits, and go online it goes online but the file changes to "copy of --.RSS", and the changes are not there.

I suppose I will do a download of the recent file later today, will that put the new version into the MM?

Will I have to do a download, every time I want to change the slightest thing? Now that the processor has been replaced, and doesn't fault anymore, it seems hardly worth it if that's going to be the case.

Should I possibly, do the download this afternoon, with these 2 S: bits disabled so I don't have to shut down the plant to make a change that will last through a power outage?

Any advise would be much appreciated,

Thank You,
Byron

 

[Caveman]

When you do online edits they are saved to the controller not the mm. You'll have to save to the mm to keep the changes.

 

[bawaller]

Thank you Caveman. Does a download save to the memory module, or do I need to do something specifically related to saving to the MM?

 

[OkiePC]

Thank you Caveman. Does a download save to the memory module, or do I need to do something specifically related to saving to the MM?

You need to specifically save the file to the memory module. This will require the controller to be placed in program mode briefly which will interrupt the process which is being controlled.

I don't have the software in front of me, but the actual menu item you are looking for is called (working from memory) "store to eeprom".

I believe it is under the Communications main menu item.

 

[Operaghost]

The memory module is intended to be a safe copy of the program. Think of it like a copy of the project stored in a vault. You don't want people just randomly making changes to that safe copy. We want to lock it away and only change it when absolutely necessary. Your computer doesn't even have the ability to write directly to it.

No, downloading does not save to the MM. And though we can automatically read from the it, there is no automatic way to write to the MM. The only way to save to the MM is to shut down the controller (Program mode) and use the RSLogix software to tell it to copy the existing program in RAM to the MM. That's important. The controller copies its RAM to the MM. We do not write it from our computer to the MM. So setpoints, values, and logic in the RAM cannot be changing when this is done. That is why we have to go to Program mode.

OG

 

[bawaller]

Many thanks OkiePC and Operaghost!

That really clarifies things. I think I will leave the vault program alone and disable the "load on boot" bit. It will be a functional version just in case I need a last resort.

Thanks,
Byron

 

[Caveman]

Thanks Operagoast, I didn't realize that the Plc ram was used to write to the eprom. I have have never done an eprom write, just new the the online edits were stored in the controller ram not the eprom.

Makes sense that the controller should be in program mode.

 

[Ken Roach]

think I will leave the vault program alone and disable the "load on boot"

Hold on just a moment; that might not give the results you want.

When the controller boots up, its operating system checks to see if there's a memory module installed. If there is, it checks the loading options that are saved on the memory module and follows their directions.

So just setting the "load on corrupt memory only" bit in battery-backed RAM won't do the job. You have to set that bit, then save the program to EEPROM, so that the controller has those settings on the EEPROM module to use at power-up.