AC jr and Leap Seconds

J

Justin02

I found that the time on my new AC Jr is slow by 291 seconds every day, which over a period of a few weeks considerably changes my lighting schedual. The manual talks about leap seconds, but in smaller terms of like 1.5 sec/day. I entered in the leap second value a few minutes ago, and it caused some strange things to happen with the clock, I guess i'll wait untill tomorow and see if it corrects itself.

So is it normal for the time on neptune controllers to be off by this much every day? Seems a $3 watch can keep better time than my $300 AC Jr :cry:
 
Someone on another forum did the same thing:

... The leap second thing confuses me because my clock is off my about 6 minutes every 24 hours so 6minutes x 60 seconds per minute = 360seconds that need to be added on the leap second function said:
The leap second feature is not just a 24 hour adjustment. You figure out how many seconds your' clock is off after 24 hours and put that amount in. That will adjust the amount of time the controller thinks 24 hours is. Mine was way off when I got it. Something like three minutes fast. Now it runs great! Hope this helps. said:
Here's the page of the thread where they are discussing it:

http://www.reefsanctuary.com/forums/equipment/18160-neptune-aquacontroller-21.html
Click to expand...
Click to expand...
 
McDonald's puts watches in "Happy Meals" that keep perfect time. It seems like adding an accurate clock to a high tech piece of equipment like an AquaController would be a no-brainer but it's obviously enough of a problem that they added a function to account for the inaccuracy.

Go figure. :roll:
 
Well I adjusted as according to directions as far as I can tell, and I"m already 1.5 hours off. Pneumatic, thanks for the link, maybe I"m reading the explanations wrong, but it's not working for me.
 
Doesn't it have a 9v battery? Have you tried replacing that? I don't know that it would have anything to do with it's time-keeping ability but it's worth a shot?
 
Right, but they have a battery for backup of the clock and settings. I would just be curious if somehow that helps regulate the time as well.

It was just a thought. :)
 
Well I havent thought of that nor changed it out, but I've only had the thing a month or so. Just left the guys at neptune a message, maybe they will enlighten me tomorow.
 
Well I didnt consider aquanotes because the computer is not near the tank for a hardwired connection. I guess there's a way to run it wireless maybe?
 
/tagging along.

My last ACJR only accounted one minute out of every SEVEN, I had to send it back to them and get a replacement. The new one was off a few minutes every day.

I have about 200 or so "leap seconds" set, and my clock was off by only two minutes after a full week.

This is serious garbage, cheap $1.00 watches from china keep better time than a $300.00 controller.
 
Think I found the solution. I read an old thread on RC that recommended powering down the unit before and after the leap second value is entered. This seemed to work for me this morning after a 12 hour period. Today, somebody from Neptune returned my call and verified the powering down solution. I told them to put it in their next instruction manual :D
 
I believe the poor time keeping ability has to do with the fact that they are
deriving the "clock" from the CPU clock and the faster the clock the more in accurate the time will be. Those of us who remember the "PC" "XT" etc computers did a pretty good job but as PC's got fater their internal time got worse. I'd hate to see what my current PC would do without syncing with the internet.

So your cheap free watches use a xtal that runs a watch fine but would be way to slow for a modern CPU.
 
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