SATEC EM720 Operation Manual - Manual (Page 78)

Chapter 5 Configuring the EM720
General Meter Setup
78 EM720 Power Quality and Revenue Meter
Display Label Parameter Options Default Description
End Day DST End Day Sunday-
Saturday Sunday The day when DST ends.
End Hour DST End Hour 1-6 2 The hour when DST ends.
Date Order Date Order MM/DD/YY
DD/MM/YY
YY/MM/DD DD/MM/YY The display date order
Clock Sync Time
synchronization
input
None
IRIG-B
SNTP
DI1…DI8 1PPM
DI1…DI4 1PPS None The external port receiving the time
synchronization signal
Daylight Saving Time
By default, the daylight saving time option is disabled in the
EM720.
When the DST option is enabled, the meter automatically
adjusts the clock at the predefined start/end time when
daylight savings time begins/ends.
When the DST option is set to Scheduled mode, the only DST
start/end hours are used, while the DST switch dates are
taken from the TOU calendar (see
Configuring the Season
Tariff and DST Schedule ). If the DST switch dates are not
found in the calendar for the present year, the meter uses
the dates you defined in your Local Settings.
When the daylight savings option is disabled, the device clock
should be manually adjusted for daylight saving time.
Time Synchronization Sources
The EM720 can synchronize its clock with a remote SNTP
server via the Internet, or receive the time synchronization
signal either from a GPS clock with an IRIG-B time-code
output, or from an external device providing second-aligned
(1PPS) or minute-aligned (1PPM) pulses.
Using the IRIG-B
Select the GPS IRIG-B option and connect the GPS master
clock to the meter IRIG-B input. See
Meter Clock and Time
Synchronization for the IRIG-B input location.
The EM720 automatically synchronizes its clock with the GPS
time each second, normally with accuracy better than one
millisecond if the time is locked to the GPS satellite time.
When the GPS clock loses the satellite, the clock continues to
generate the IRIG-B time code referenced to the last
available satellite time (called unlocked time), but the time
quality may get worse. Such losses may continue from a few
minutes to hours. The time code generated during outages is
typically accurate to within a few milliseconds over a 24-hour
period.
If the signal from the GPS master clock is not detected on the
meter input, the EM720 changes the time synchronization
source to the internal RTC in 10 minutes after signal is lost.