In theory, each M-DCU could manage 256pcs S-DCU within 2km, each S-DCU could manage 256pcs meters within 2km.
The administrator operate computer to manage through M-DCU first by RS485 on-line, then S-DCU, then to meter.
Each Meter has pre-paid function. After user purchased energy beforehand, the meter start to work.
Each Meter can set the starting time (eg: 6:00pm) everyday when the new allocation will begin. As soon as the designated time (6：00pm) is reached, the new allocation will take effect.
Each Meter can set daily limit of energy consumed.
When the daily limit is reached, the buzzer will beep for alarm first ( beep 1 sec after 4 sec ), then the meter will automatically cut off the load power, until the next day, an new kWh allocation is provided and take effect when the designated starting time (6:00pm) is reached.
When purchased energy used up, the meter will also automatically cut off the load power, until user purchased new energy.
It runs in circle this way.