Landis+Gyr ZFQ202, User Manual

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Gyr H 71 0200 0215 f en - ZMQ202 / ZFQ202 - User Manual
22/88 Description of Unit
2.6 Calendar Clock
The internal calendar clock of the ZxQ is used to generate the date and
time information which is used:
• for the date and time information to be displayed
• for the time stamps in the load profile and event log
• for the formation of the capture period of the load profile
• to control the time switch
Calendar clock
Internal
capture
period
Network frequency
50/60 Hz
crystal
Capture
period
synchronous
capture
period
Synchronising
Date and time
The clock uses a crystal as time base. The clock may be driven by the
network frequency (50 Hz or 60 Hz), provided it is sufficiently accurate.
Tuning is then performed after each full wave, i.e. after 20 ms at 50 Hz.
The clock features an accuracy according to IEC 61038.
The calendar clock can be adjusted by an external master clock via the
synchronisation signal Syn or via communication. The period is adjustable.
A supercap (capacitor of a very large capacity) provides the power reserve
of the clock. The power reserve may be extended by the use of a battery.
• Power reserve without battery: min. 20 days (only after the meter has
been connected to the network for at least 300h)
• Power reserve with battery: 10 years
2.6.1 Adjusting the Calendar Clock via the Synchronisation Input
The calendar clock can be adjusted by an external master clock (e.g. the
central station), which sends synchronisation pulses at regular intervals.
There are two possibilities of adjusting the calendar clock using the
synchronisation signal Syn:
• The adjustment takes place several times throughout the day.
• The adjustment takes place once per day.
Note
Usage of only one type of adjustment
Only one type of adjustment can be used at a time, either several times
per day
or once per day.
Time base
Accuracy
Synchronisation
Power reserve