Saving to CF Card

[slickfix 0]

I have about 8 plcs I maintain at our sewer plant. They are all compactlogix 1769-L32s. I have bought AB CF cards for each PLC. The reason I bought the cards is to restore the program to each plc in the event of memory failure due to glitch or battery failure. My boss would rather do it this way instead of using software. (I have RSLogix 5000.) I have a few questions for you members. Once the program is stored, he wants the CF cards removed and stored in a safe place. 1) Is only the program lost on memory failure and not the firmware? or both? I alaways thought the firmware was non-volatile. 2) I am confused by the Firmware Update checkbox. Not explained very well. Should I check this box, Is it really needed, and what is the proper procedure. Thanks, Eric Edited 20 Apr 2015 by slickfix

[Ken Roach 194]

The firmware is nonvolatile, but you have the option to include a firmware update in the process performed by the CompactFlash memory card. This was done so that you could load a CF card with firmware and a user program and set it for "load always" then ship it to a remote site. Installing it and rebooting would cause a firmware update and a program update automatically. In general I do not use the firmware update feature when I store CF cards or image files of ControlLogix and CompactLogix controllers. For CompactLogix 1769-L32E controllers, I would set the CF card restore mode for "On Corrupt Memory" so that it can be done in the event of an inadvertent memory loss (power spike, dead battery, etc) and you can also just pull the battery and cycle power to create the same conditions.

[slickfix 0]

Thanks for the quick reply Ken. Thats what I needed to hear. I really didn't want to mess with the firmware. Thanks again, Eric

[slickfix 0]

Hi all,

I recently had a processor failure and replaced it with a new processor. (I am the same person that had this original post.) To my dismay,

the CF card would load since there was no firmware on the new processor. I had to manually load the fireware using software to the processor to make the CF

card work. I am now wondering whether I should have backed up the firmware also. (Which I really did not want to do.) It seems there could be trouble if you

update the firmware also.

 

Or should I have loaded all my spare processor modules with firmware? Problem is, I don't know know whether all my plcs (We have about 8) have the same

firmware. What would be the best thing to do? They are all the same number and type of processor.

 

My boss wants to be able to restore the processor without software on a loss of memory or failure. When you save the firmware and program to the CF card

does the exact same firmware and program from the CF card get loaded back onto the processor? The reason I ask is the term "Firmware Update" is confusing to me.

I don't really what to update the firmware, I just want to copy back what was saved before, not a newer version. Or is that what update on the CF card does?

 

Thanks Again,

Eric

 

 

 

[Joe E. 259]

As you saw, new processors come without the firmware you need and therefore need to be updated to what the program needs.  I would spend the time it takes to figure out what firmware versions you have in the plant for each model of PLC.  Since you only have 8 PLCs, it won't take long to open each project and see what they're set to.  If have the ACD files handy but not the PC with RSLogix, you can open the ACD file in notepad.  The first section of the file has a sort of revision history.  If you scroll to the bottom of that section, you can see the last version of software used with the project.

If all of your PLCs are the same version, you can flash your spare to the right version.  If not, I would consider upgrading the older ones to the newest if you can.  If you can't change what's in the field, then having the CF card set to update the firmware is probably your best option.  I would also research the behavior of the CF card on each reboot.  If it only flashes the firmware when there's a difference between the CF card and the PLC memory, you're fine just leaving that box checked. 

Also note that the CF card will have the version of the program and run-time data values active when it was created.  Any run-time values that have changed and any program changes since then will be lost if you store the CF card externally and don't update it periodically.