1. Mechanical wheel and LED digital tube double display, the mechanical wheel can still display when there is a power failure or unexpected accidents, which can avoid disputes between the users and power management department.

2. It will alarm automatically when there is only 100 KWH electric power left, and power will be cut off when there is 20 KWH left, secondary alarming function is unique in China (the remaining electric power can be resumed after inserting card by the user, and continue to be used).

3. It adopts data automatically correcting technology; Every piece of data is stored separately in 5 places. In case something is wrong with one datum, data in other four places can correct automatically, thus it is absolutely reliable and safe.

4. The components of IC card all adopt famous industrial parts, and key elements use original chips of US and Japan, such as the measuring chips adopt AD7755, which ensure quality of the elements and the whole meter.

5. It adopts contactless IC card (RF card) patent technology which transmit wireless data outside the meter, thus with a function of waterproof, damp-proof and anti-attack.

DDSY201F adopted RF IC Card technology and more advanced than DDSY201 and the technique parameters of the two watt-hour meter are the same.

Main Functions of Single-phase Prepayment Watt-hour Meter
Single-phase prepayment watt-hour meter can supply electric power only after being prepaid by users firstly, one card for one household and one meter, and not interchangeable. When the electric power in the card is used up, the power will be cut off automatically, thus effectively avoid inconvenience of fee-charging.

Meanwhile, the computer controls the electric power purchasing information of users, which is convenient for inquiring, summing up, fee-charging and bills printing, etc. The various technical parameters of single-phase prepayment IC card watt-hour meter are in accordance with standard of GB/T17215-1998 Grade A and Grade B Static AC Active Watt-hour Meter and the technical requirements for Prepayment Watt-hour meter. It adopts the most advanced IC card technology and SMT technology in China, with complete function of double display, precise measurement, stability, safe and reliable, low power consumption and is easy to operate.