Lost project in Logix5000 ？

Hi, guys, how’s going?

One production line lost the communication after we rebooted the power. We found there was no project loaded on that Logix5000 controller.

We downloaded the program from PC to PLC and the communication is back.

But I still have some questions:

1, how did it happen? There is no battery alarm, but we lost the project.

2, plz see the attachment, if I am not sure the top .ACD is the current one (because different people can use different computers to access to the controller), the bottom .ACD with date 11/24/2015 is the latest one, right?

3, how to compare two logix5000 projects/programs?

Thanks a lot.

What model ControlLogix? The older ones used batteries, the newer ones don't. There is a compare utility that you can download. If your asking about the four files shown, the one without the BAK in the name is probably the most recent (12/21/2015). Logix 5000 makes backup versions every time you save the project.

There is a Logix5000 Compare Tool that you can install along with RSLogix5000.
Its one of the additional options you check boxes during install.
You can rerun RSLogix5000 install at any time and install this additional option without affecting existing installation.

Compare Tool typically shows up in the "Start" -> ""Programs" -> "Rockwell Software" -> "RSLogix 5000 Tools" folder

The topmost file is the actual file; the other 3 are backups that, as John says, are created each time you save the project. So the BAK180 file there is your most recent backup and is likely up to date - most people tend to save multiple times before closing a project so it's likely that no edits were made between that backup and the current file. Of course, the only way to really prove that is (as John said again!) the compare utility.