rslogix 5k fault clearing

on a controllogix 5k 5571, I got red light at the OK indicator. I'm not sure whether it was solid or blinking. Anyway, being a newbie, maintenance guy, I just got online and cleared it without checking the controll property menu's fault tab.

In the RSlogix5k help file, I got the following
"To clear a major fault from the controller keyswitch:
1. Move the keyswitch from the RUN or REM position to the PROG position.
2. Move the keyswitch from the PROG to the REM position.
3. To restart the program, move the keyswitch from the REM to the RUN position.
The OK LED on the controller should change from blinking red to solid green, and the RUN LED on the controller should be solid green.
4. To not restart the program, move the keyswitch from the REM to the PROG position.
The OK LED on the controller should change from blinking red to solid green, and the RUN LED on the controller should not be illuminated.
Note: This clears the major faults but not the major fault log (displayed on the Major Faults tab)."

So, based on that, next time, I will use the REM->PROG->REM->RUN method, to start the process, then turn it back to REM.

Question #1) Now, did I just lose the fault log? I know the help file says "this clears the major faults but not the major fault log." But, does it only applies to the #4 method (REM->PROG->REM->PROG), or does it also applies to #3 method (REM->PROG->REM->RUN)?

Question #2) does the same underlined statement also apply to the minor fault log as well? In other words, would I retain the info under the minor fault tab when I use either the #3 or #4 method?

So technically, you need to go Prog ==> Run ==> Prog to clear the fault. Remote (REM) won't do the trick.

No, you do not lose your fault information clearing the fault in this manner. For some odd reason a previous Rockwell PLC called the "SLC 500" would actually clear fault information when you did this, but the 5000 system does not erase the fault information.

The 5000 will clear its fault log only if you clear it from the RSLogix/Studio 5000 software or if there is logic in the controller that executes when the fault occurs and clears the code. Toggling the key will NOT erase that information.

So it is possible to clear the fault from they key and then go get a PC to view the fault code. Now we are assuming another different fault doesn't occur which would overwrite the previous code. Plus, of course the safety concern of clearing a fault and putting a system back into Run before we know why the system shutdown in the first place.

OG

Operaghost said:

So technically, you need to go Prog ==> Run ==> Prog to clear the fault. Remote (REM) won't do the trick.

Click to expand...

But according to the help file, I am supposed to do REM->PROG->REM, then either RUN or PROG. The paragraph in quotation in my original post is what I copied and pasted from the help file. I don't get it.

Operaghost said:

So it is possible to clear the fault from they key and then go get a PC to view the fault code. Now we are assuming another different fault doesn't occur which would overwrite the previous code. Plus, of course the safety concern of clearing a fault and putting a system back into Run before we know why the system shutdown in the first place.

OG

Click to expand...

Great point. Thanks, OG.

The Help is wrong. Seriously, it is wrong. I've been teaching people how to use the Logix 5000 for nearly 15 years. It really is wrong. Just going to REM will not do the trick.

The following is from a Tech Note (#42003) on the RA Knowledgebase.

A major recoverable fault occurred on the controller. To clear the fault:
1.Turn the controller keyswitch from PROG to RUN to PROG.
2.Go online with RSLogix 5000.

OG

Operaghost said:

The Help is wrong. Seriously, it is wrong. I've been teaching people how to use the Logix 5000 for nearly 15 years. It really is wrong. Just going to REM will not do the trick.

The following is from a Tech Note (#42003) on the RA Knowledgebase.

A major recoverable fault occurred on the controller. To clear the fault:
1.Turn the controller keyswitch from PROG to RUN to PROG.
2.Go online with RSLogix 5000.

OG

Click to expand...

Since REM is the usual position when the fault occurs (at least for me), actually the method is from REM to PROG, back to REM, to RUN, back to REM to PROG? Then, if I want to run, from the PROG to REM to RUN?

correct.

og

Fault recovery

I have a customer with a machine running a Compact Logic L35E password protected processor - no we don't have the password. The machine builder has locked it down.

Recently the customer attempted to recover from a faulted processor (according to them, no record of what the fault was) using the keyswitch method, I can't say exactly what they did.

When I arrived the PLC was not in a fault state but the IO LED was not lit and there were no outputs on, there is a stack light so if the program is running something has to be lit. There was no communication with the HMI.

I reloaded the PLC program with a compact flash card and then corrected some communication settings in the Panelview 700 plus which I think the customer messed up when the PV said it couldn't communicate with a PLC which wasn't in the RUN mode, don't know for sure.

I have a list of the processor fault LED codes, i.e., which LEDs on the unit are on, what color and/or flashing.

The machine also uses device net. Not sure about trouble shooting codes on that. I haven't had problems with device net in the past that were not painfully obvious.

I'm trying to come up with a "before you do anything when it faults at least write down what state these particular things are in!" list so when I get there after they have done whatever they do I have half a chance of actually fixing the problem. The damned PW protected processor isn't my best friend right now....

Thanks,
Jon