STS is the Standard Transfer Specification, an international standard recognized and published by the International Standards Institute. It was originally developed in South Africa. In 1997, the STS Association was established in South Africa and was standardized as IEC62055 by the International Standards Association in 2005. It mainly provides reference for the realization of electricity meter encryption, decryption and prepayment.
The STS code type prepaid meter transmits a series of instructions such as electricity purchase code (Token), encryption and decryption, and key management according to this specification. Electric meters that support the STS protocol have the characteristics of unique key, unique token, and unique verification, thus ensuring the uniqueness and security of the token.
The STS meter has all the features of a prepaid meter. A prepaid meter means that the user buys electricity first and then uses it. When the user runs out of electricity, the relay will automatically disconnect, so that the user can not continue to use electricity. After the user purchases new electricity, the relay is automatically closed, and the user continues to use electricity, which solves the problem of difficult charging by the utility company.
STS meters use tokens to manage electricity. A token is an STS (Standard Transmission Specification) compliant 20-digit number issued at the time of purchase, which will discharge a specified amount of electricity (in kilowatt-hours) on an STS smart prepaid meter. Using tokens can avoid the cost of printing and purchasing IC cards. Users can obtain electricity purchase codes by printing notes, text messages, the Internet, etc. and complete the recharge by themselves.
There are two types of token-type prepaid electricity meters: integrated type and split type. The all-in-one machine is an integration of a token keypad and an electricity meter. All you need to do is press the keypad on the meter and enter the token to complete the interactive functions associated with the meter. The split meter is the token keypad and meter split. One keypad can be connected to one or more prepaid electricity meters. The keypad (customer interface unit) can be installed indoors or outdoors, and the meter can be hidden in a pole-mounted meter box.