Temperature; Real Time Clock - Landis+Gyr E470 User Manual

Page 10 of 69
3.3

Temperature

3.4

Real Time Clock

© Landis+Gyr
Issue: 1.8
FRAM is capable of a minimum of 10,000,000,000 write cycles and does
not require power to maintain the stored data.
To indicate active energy usage the meter is fitted with a single red LED.
When registering energy the LED will flash at a rate of 1 pulse per Wh of
energy recorded (1000 pulses kWh). Each pulse shall have an on time of
20 mS. The metrology LED will be configurable to show forward or reverse
energy consumption for test purposes. The metrology LED will be
permanently on when creep lock is active.
The operating temperature range is –25°C to +55°C.
The storage temperature range is -30°C to +85°C.
The Meter has a real time clock, optionally configurable to synchronise to
the mains frequency in normal operation. When the meter is configured for
mains synchronisation, the clock shall maintain the same stability as that of
the mains, i.e. within ±30 seconds/year.
During periods of power failure the time shall be maintained by an internal
battery powered, crystal controlled clock. In battery backed mode the
accuracy shall be maintained to within 15 minutes/year at a temperature of
20°C.
The time is displayed in 24-hour mode.
The meter operates on GMT with the option to operate with scheduled
changes for British Summer Time (BST) applied to customer timed
functions, i.e. Tariff Switching Times, No-Disconnect Period and the clock
displays in Customer Displays.
The meter may be configured to remain in GMT throughout the year with no
change for DST.
If configured to operate with DST changes, during the BST period the meter
shall display the BST clock time, the rate-switching matrix and any timed
events shall operate on the BST time clock.
DST setting is configurable allowing standard European settings or any
other combination of DST settings. Configurable settings:
 Start and end calendar month
Start and end week, first –forth or last

Start and end day

Start and end time

 Adjustment hours
The real time clock may be set using the optical port.
Functional Overview
E470 Tokenless Smart Prepayment Meter