6K V1.02 03-16-91
95
CLOCK
INTRODUCTION
The controller features a software clock and calendar. As long as power is supplied to the
controller, it will keep proper time. The calendar does not have leap-year correction.
CLOCK CORRECTION
Command Form:
(PW) 19 (00-59 sec., 0=slower/1-faster) *
Description:
This command allows you to "tweak" the clock for precise accuracy.
Acknowledgement:
OK
Errors:
? ERR 1
? ERR 2
Default Condition:
No correction is assumed
Examples:
Assume that the clock is running one minute fast per month. The daily
correction would be 60 seconds divided by 30 days, or 2 seconds per day.
The clock should be running 2 seconds per day slower. The command
would be:
(PW) 19 02 0 *
As a second example, assume that the clock is running 5 seconds slow per
day. The correction command would be:
(PW) 19 05 1 *
It will require several days to note the amount of correction needed, since it
will become obvious only after at least 1 minute of error accumulates.
Therefore, you should divide the number of seconds of error by the number
of days over which it accumulated: this will yield the daily correction.
Note that corrections are not cumulative; a correction of 2 seconds fast,
followed by a correction of 4 seconds fast does NOT result in 6-second fast
correction. So, if subsequent checks show the need for additional
correction, the old correction value should be replaced with a slightly larger
or smaller correction value. Setting the clock and calendar does not affect
the correction. If the clock is changed for daylight savings time, for example,
its accuracy will not be affected.
