User's Manual

Title:
AJ102 Data Concentrator Unit User Manual
Ver.
1.4
Page:
9 of 23
4 Function Characteristics
4.1 Clock Management
DCU has a RTC which complies with IEC 62052-21/62054-21. At reference voltage and reference
temperature (23°C), clock accuracy is better than ±0.5 s/day.
The RTC supports leap year, day light saving time. In case of power off, clock of DCU is active for at least
two years after manufactured with battery support.
DCU automatically synchronizes its clock with SNTP server every day.
The central system can synchronize the DCU’s clock.
When the DCU’s clock is invalid, DCU will not automatically collect the data from meters.
4.2 Synchronize Meter Clock
DCU automatically synchronizes the clock of the meters once a day.
DCU interrogates the clock of meters. Depending on the clock difference, DCU take following action:
Clock difference
DCU action
≥10 minutes
Record a clock over limit event for the meter.
≥ 5 minutes
And < 10 minutes
Set the clock of meter
< 5 minutes
No action, the meter’s clock will be synchronized in next day’s clock
synchronization procedure of DCU.
4.3 Node Discovery and Auto-routing
DCU automatically discover the new-installed RF repeater. Automatically routing will be provided by DCU
for RF repeater. DCU supports maximum two levels of RF repeater.
Once DCU discovers new meter, if the meter is not registered in the DCU, DCU will report this meter to
central system, then central system will download the meter archive information into DCU.
4.4 Automatically Meter Data Collection
DCU automatically collects the data from single phase meter, three phase meter with direct connection and
three phase meter with CT connection. The data type for automatically connection includes monthly billing
data, daily profile data, load profile data, and meter event logs. It is configurable to enable or disable the
data collection for each type of data.
4.4.1 Re-collect the Data
In case of missing some data for the meters, DCU will automatically re-collect it from the meters:
Data Type
Re-collection Period
Monthly billing data
Last month