Re: x10 - CM12U (CM11) Clock Accuracy

[Charles Sullivan <cwsulliv@xxxxxxxxxxxx>]

On Tue, 25 Sep 2007 21:14:31 +0000, Jeff Volp wrote:

> "Martin Davies" <martin@xxxxxxxxxxx> wrote in message
> news:1190753236.75757.0@xxxxxxxxxxxxxxxxxxxxxxx
>> Hi -
>>
>> Thanks for this. Do I understand from your message that the CM11/12 uses
>> the mains supply frequency to regulate its internal clock? If so I may
>> have a problem as we are connected to a private generator supply and the
>> frequency does vary somewhat. Even so the variation in frequency doesn't
>> account for the large errors I'm experiencing with timed events.
>
> A private generator (not connected to the grid) could certainly be a factor.
> One Onan manual for a RV generator says it should run at 63Hz no load,
> dropping to 60Hz under full load.  Even if the generator is only a few Hz
> off, that can accumulate to a clock error exceeding an hour a day.  However,
> that same error would also show up in any other electric clocks that take
> their reference from the same powerline.
>
> As I recall from the CM11A beta test, it updated the clock whenever it was
> connected to the PC.  So it would never register a clock error.
>
> Jeff

Jeff,
I believe ActiveHome will only update the CM11A clock on user
command -or- (automatically and silently) if AC power to the CM11A
has been interrupted. The OP never stated whether or not he
unplugged his CM12U from the AC socket when he disconnected from
the computer.