Micro 820 switching to programming mode by itself

[RMore]

Has anyone ever heard of a Micro820 PLC with a Remote LCD HMI automatically switching to programing mode?

I know the PLC's are running hot, but I can't imagine a situation where the PLC would change from normal RUN mode to PROG mode on it's own.

Any ideas?

 

[gclshortt]

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/2080-um005_-en-e.pdf

Advanced Set - PwrUp Behavior - Configure controller mode on power up
I would check the above setting to ensure that the controller is set for run mode when power is applied. The supply to the controller may be dropping off causing this to go into program mode.

Just a thought.
Regards,

 

[PLC Pie Guy]

I have two identical machines built within a couple weeks of each other. Both with the very same cabinet and the very same Micro820. 24VDC supply and I/O. Typically, I USED to set my Micros to "Retain Previous State On Power Cycle" for the startup mode. Always leaving it in RUN mode, it shouldn't be a problem. However, one of the machines mentioned above has a tendency to switch to program mode if the power gets cycled before the boot is complete. I can re-create this probably about 80% of the time. The other machine, I can't make it happen with 100 power cycles.

Now, I set the startup option to always start in run mode.

Not sure why it is, but it is!

 

[damica1]

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/2080-um005_-en-e.pdf

Advanced Set - PwrUp Behavior - Configure controller mode on power up
I would check the above setting to ensure that the controller is set for run mode when power is applied. The supply to the controller may be dropping off causing this to go into program mode.

Just a thought.
Regards,

Power Supply?? I have run into strange behavior when power supply is too small or failing.