Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (S)
Guardian Procedure Calls Reference Manual—522629-013
14-121
SETSYSTEMCLOCK Procedure
timestamp. This mode is used for precise time synchronization with a hardware
clock or for a moderately precise method of operator time adjustment.
tuid input
INT:value
is a time update ID obtained from the JULIANTIMESTAMP procedure. It should be
used with
mode 2 and 3 to avoid conflicting changes.
Condition Code Settings
< (CCL) indicates one of the following:
•
insufficient capability
•
time specified by user is out of range (01 JAN 1975 0:00:00.000000 to
31 DEC 10000 23:59:59.999999)
•
julian-gmt is not supplied; invalid mode; or tuid does not match.
•
requested adjustment exceeds one hour and mode specified is 6
= (CCE) indicates that the SETSYSTEMCLOCK was successful.
> (CCG) is not returned by SETSYSTEMCLOCK.
Automatically Adjusting the Clock Using Modes 0,1,2,3,6
•
If the value of the mode parameter is 0 through 3 and the clock error is two minutes
or less (as determined from the user input), the system adjusts the clock rather
than sets it. If the value of the
mode parameter is 6, then regardless of the clock
error, the system adjusts the clock rather than sets it. The system adjusts the clock
by very small amounts. For example, if the clock is slow, making a change of two
minutes takes about 33 hours; if the clock is fast, making a change of two minutes
takes about 14 days.
•
When making an adjustment, SETSYSTEMCLOCK tries to determine the clock
rate error by relating the clock error to the time elapsed since the clock was last
set.
•
If you call SETSYSTEMCLOCK, if the mode parameter is not 6, and if the clock
error is greater than two minutes, then the system stops any ongoing adjustment
and sets the clock.
•
If you call SETSYSTEMCLOCK with a mode parameter value of 6, and the
requested adjustment exceeds one hour, CCL is returned.
Setting the Clock Using Modes 5 and 7
•
If the value of the mode parameter is 5 or 7, regardless of the clock error, the
system sets the clock.