Fault and Alarm Management RSLogix5000

Hello All,

Just wanted to gather peoples' thoughts regarding fault and alarm management within a program. I've seen programs where AOIs are used, programs where function blocks are used, and programs where XICs and OTEs are used with timers.

Just looking for a clean, professional way to organize everything. I'm using FactoryTalk View to display alarms, so a setup that works well with FTV would be preferred.

Thanks!

In my opinion it depends on the situation. AOI's are good if you already have well tested alarm AOI's that you know work well. XIC's and OTE's with timers may be easier to someone who is not familiar with the program, to troubleshoot in the field. This is my favorite way of doing alarms, because I think it's the easiest to troubleshoot and the easiest to understand by people not familiar with the system. I think some versions of RSLogix have ALMA and ALMD instructions that you can use but I forget which versions of RSLogix have these. These are for analog and digital alarms.

I have a routine called Faults that set bits in an array of DINTS that is defined in FTView Alarm setup. Straight forward, nothing fancy, allows the maintenance guy that has to support it to easily figure it out.

I did work on a project where the starting programmer made an AOI that archived faults, the status of the I/O and some key tags. There was a lot of logic with load cells driving servos and it was pretty nifty for figuring out why the system faulted or acted strangely after commissioning. Its now in my toolbox.

I tend to have an array of DINTs broken up per station for grouping and station logic. I will have a fault subroutine in the main program that will combine all of the DINTs into a large array to count all of the active faults on the machine to get total live faults. The subroutine will also create a scrolling banner on top of the panelview display using a string array in the PLC and update a pointer/total fault count. Banner text 100% gives the fault bit you can search in the program. End result is:
"

11/13 - Stn300 - Left Clamp Advance Overtime - STN300.SV[3].FAULT.3

Click to expand...

Im a big fan of using the panelview fault message for the history element but not the banner or pop up for live alarm displays, so that's why I've added the scrolling banner above. The best thing about storing all of the fault strings in the PLC is you can have the the panelview alarms pre-programmed to show the string tag instead of typing in all the messages there. If you add in a couple extra spares, putting in a new alarm is just a matter of editing a string online and adding an OTE bit instead of compiling a new MER file, downloading, rebooting..

Also on the panelview maintenance page I have a button to either latch or auto reset faults common for the entire cell. Usually it will be left to auto reset but for on the floor troubleshooting it is nice to be able to see all the things that might be causing issues.

Any testing or analog reading will have the last 5 tests displayed on the panelview for easy assessment and I will stop production after 3 consecutive failures and throw a fault and stop feeding parts.