3.6 System clock and
synchronization
3 Supporting functions
Technical description
94
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VM55.EN005
Example 1.
If there has been no external sync and the relay's clock is
leading sixty-one seconds a week and the parameter AAIntv
has been zero, the parameters are set as
s
AAIntv
Lead
AvDrft
9
.
9
61
8
.
604
With these parameter values the system clock corrects itself
with –1 ms every 9.9 seconds which equals
61.091 s/week.
Example 2.
If there is no external sync and the relay's clock has been
lagging five seconds in nine days and the AAIntv has been
9.9 s, leading, then the parameters are set as
6
.
10
3600
24
9
5000
9
.
9
1
1
NEW
AAIntv
Lead
AvDrft
NOTE! When the internal time is roughly correct – deviation is less than four
seconds – any synchronizing or auto-adjust will never turn the clock
backwards. Instead, in case the clock is leading, it is softly slowed down
to maintain causality.
System clock parameters
Parameter Value
Unit Description
Note
Date
Current date
Set
Time
Current time
Set
Style
y
d
m
d.m.y
m/d/y
Date format
Year-Month-Day
Day.Month.Year
Month/Day/Year
Set
SyncDI
DI1, DI2
The digital input used for
clock synchronisation.
DI not used for synchronizing
Minute pulse input
***)
TZone
12.00 ...
+14.00
*)
UTC time zone for SNTP
synchronization.
Note: This is a decimal
number. For example for state
of Nepal the time zone 5:45 is
given as 5.75
Set
DST
No
Yes
Daylight saving time for
SNTP
Set
