PLC-5 lost timer presets

We have a PLC-5/40 that lost some (or all?) of the timer preset values. Has anyone ever experienced something like this? The PLC is a Series C and is over 10 years old.

Were they all back to zero, or something else?

If something else, it may be that they were reloaded from an EEPROM or defaulted from a PanelView...

Or somebody could have downloaded an old program... (I know of a lot of places that the first thing they do is download a "master" program, without regard for any changes that may have been made. I still have no idea why they would have the idea that downloading a program would fix anything, but that's a topic for another post.)

OZEE - Thanks for responding. I think that the values were zeroed. Sorry that I don't have any more info than this. (I got my info 3rd hand.) They do have a Panelview.... could this have zapped the presets, maybe due to a communications glitch? Thanks.

Panelview can be set to download some preset values on startup. It's NOT the default setting, it's something you intentionally have to configure within the PV's.

Recently, I've had some issues with PanelMates sending errant data over DH+ to a SLC. Not sure exactly what's up with that, but it's happened to me twice on the same system in the last couple of months.

jeller said:

OZEE - Thanks for responding. I think that the values were zeroed. Sorry that I don't have any more info than this. (I got my info 3rd hand.) They do have a Panelview.... could this have zapped the presets, maybe due to a communications glitch? Thanks.

Click to expand...

IF the Panelview (Panelbuilder communication tab under system folder) is set to "Write to controller on power up" it will send the "initial value" of all the tags whenever it is started.

I find a lot of applications set up this way, and it has bitten me more than once.

Thanks OZEE and OkiePC. I will investigate the Panelview angle.