R2 won't auto-run

I have an older SNAP-PAC-R2, from 2013 (S/N 674XXX), and it doesn’t want to auto-run its program even though it’s being (supposedly) stored to flash, and has the auto-run box checked as well.

Substituting a different R2 for this one, everything works fine with the same strategy and the development system settings all the same, too.

This unit is old enough that the rechargeable battery may be going bad, although I read a bit over 3.00 Volts on it while connected to the board, so presumably under whatever small load it will normally be under.

Is auto-starting of the strategy dependent on the battery?

And while we’re at it, are persistent variables also dependent on the battery?

I have some of these batteries on order, but I’m now curious about what all relies on the battery for retention in R1 and R2 PACs.



I think this is the memory map guide you seek…

Indeed, that is exactly what I needed to see. Thank you for that. I will see how the unit runs with the new battery when they arrive, and hopefully the new battery will breathe fresh life into that controller.

I appreciate the quick answer. The use of battery-backed memory to store the persistent variables makes perfect sense because one will likely be writing to them in loops, so to preserve them in flash would require the controller to desperately copy them to flash all at once as power was failing, which would be silly now that I think of it!

The auto-run flag being stored in Battery-backed RAM is likely the reason I’m seeing this symptom in this controller. It’s a good reminder that I should probably swap the rechargeable as well as primary cell batteries in a lot of the controllers I have in use.

This should probably be in a maintenance schedule of mine. Is there any advice about the lifetimes one can expect from these primary and secondary cells under various conditions? For example, will having spare controllers stored and not powered) tend to reduce their battery lives, and is that situation different for controllers that have rechargeable cells versus primary cells?

I like to keep backup controllers on hand for everything so I can get things running quickly if we have a failure. But I can imagine the stored units having battery problems as fast or even faster than the working units.

Then again it might be more of a shelf-life time regardless of whether or not the unit is in use, or stored, and may be about the same for units with rechargeable and primary cells.

These controllers have been so reliable for us that I tend not to even think about any of this. I do remember swapping out the lithium primary cell in a Mystic M4 way back, and that’s it. I’ve never experienced even a single hardware failure in any opto module or controller. Ever. Not one, in 25 years.

But I still insist on keeping spares for everything in the systems that we use in our municipal drinking water plant and pump stations. I need to consider how often to swap batteries, and how often to refresh my supplies of stored spare cells, as well.

Thanks again for your fast help. I know I could have searched and found that document on my own, but you guys make this really easy! Just one more reason why I prefer using the Opto 22 equipment!

Glad we could help.

It is really hard to quote hard numbers because of the variability of batteries and temperatures.
Also, the battery brand/quality will impact the storage and lifetime numbers.

Here is our guide on the batteries in the PAC Controllers, it may of assistance in answering your remaining questions;

That makes sense. There’s no way to predict battery life reliably without knowing the particulars.

That document at least shows retention times, which is interesting. Thanks!