Zennio KEM, User Manual, Page: 10 / 49

KEM
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1.5 SETTING THE TIME OF DAY
For certain functionalities, such as periodic registers or the starting date of each register,
it is necessary to set the time of day of KEM through a master clock in the installation.
During the start-up, KEM will request the time of day to the KNX bus through the objects
“
Date
” and “
Time of day
”. Up to four read requests will be sent (after a customisable
initial delay). If there is no response after these four requests, the device sets the last
known date and time.
Notes:
The time count is performed internally by KEM. However, any time adjustments
must be notified (through external events) in order to ensure the
synchronisation of the periodic timing of the registers.
Periodic synchronise of the internal clock of KEM is advisable to prevent
precision loss after prolonged operation. Therefore, KEM sends a time request
to the KNX bus every 15 minutes.
Please take into account that the device does not start measuring until it has a
valid date and time.