Re: x10 - CM12U (CM11) Clock Accuracy

["Jeff Volp" <JeffVolp@xxxxxxx>]

"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