Accuracy; Date And Time; Validity; Daylight Saving Time - Landis+Gyr E470 Series User Manual

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3.5.1

Accuracy

3.5.2

Date and time

3.5.3

Validity

3.5.4

Daylight saving time

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The calendar clock uses an internal crystal as time base.
The crystal features a maximum deviation of 0.5 s per day (<6 ppm) i.e.
maximum deviation of the calendar clock is 15 seconds after 30 days.
The clock maintains its accuracy in accordance with the requirements of
SMETS2 and GBCS. The calendar clock can only be set with the GBCS
command ECS70 "Set Clock on ESME" and will automatically synchronise
with the communications hub every 24 hours and on power-up. The setting
of the time is recorded in the standard event log.
The approach is as follows:

The energy supplier sends a Set Clock command with the supplier's
current time and a future time (reflecting a time tolerance) in the
command; and

if, when the meter receives the command, the communications
hub's time is within tolerance of the energy supplier's time, the
meter aligns itself to the communications hub's time and treats its
time as reliable. Otherwise the meter treats its time as unreliable.
Note that mains frequency synchronisation is not employed in the E470.
Time and date within the meter is based on normal time (UTC in the UK).
When communicating with the meter the date and time is shown (set) as
normal time. Time and date is always shown as local time on the display
(incorporating DST time shift).
The following formats are supported:

day [dd], month [mm], year [yy] on LCD, e.g. 10.01.07

hour [hh], minute [mm], second [ss] e.g. 12:30:55
Only 24-h format is supported for time. Midnight is shown as 00:00. Other
time information such as day of week is not supported.
The calendar clock is designed to generate valid calendar data (including
leap years) between 1.1.2000 and 31.12.2059.
Daylight savings time settings are only used by the meter for display of
local time on the meter display. Changeover to daylight saving time (DST)
and back to normal time is performed automatically per the DST settings
configured in the meter. Start and end of daylight saving time can be set
per the European standard or the user can define their own specification.
By selecting the EU standard, the meter will be set to start the daylight-
saving time on Sunday the 25th of March or on the first Sunday after the
25th of March. On that day, the local time is advanced from 01:00h to
02:00h.
Daylight saving time ends on Sunday the 25th of October or on the first
Sunday after the 25th of October. On that day, the local time is set back
from 02:00h to 01:00h.
When configuring a specific daylight saving time the DST parameters must
be set from the following:
D000058620 en a – E470 Series 3 SMETS2 100 mm – ZCX310 – User Manual and Functional Description
Issue 1.2 Functional overview