A token is a 20 digit (66 bit) numeric or magnetic record of the data sent from the point of sale to the payment meter. Tokens exist in several types as defined below.
The following token types are defined in the IEC62055-41 specification
Credit tokens (Class 0)
Credit tokens a a class of tokens used to carry credit from a Point of Sale to a payment meter. Several subclasses of these tokens are available for use:
Unit based tokens
Unit based tokens transfer utility units in the following categories:
|Water Credit||1||cubic meters|
|Gas Credit||2||cubic meters|
Currency based tokens
Currency based tokens transfer currency amounts in the following categories:
|Electricity Currency||4||0.00001base currency uints|
|Water Currency||5||0.00001base currency uints|
|Gas Currency||6||0.00001base currency uints|
|Time Currency||7||0.00001base currency uints|
This token type is useful when a payment meter makes use of complex tariffs such as time-of-use tariffs, where the cost of the utility depends upon the time of day. The currency denomination is not defined, therfore allowing the utility to taylor it for their currency type. The resolution is 0.00001 base units, allowing for most currency denominations.
Non meter specific management tokens (Class 1)
This token class defines the following tokens:
These tokens are not encrypted by the POS system since they are not unique to a specific meter but will work in any STS compliant meter. These tokens may be hardcoded into the POS system since they do not change. Care should be taken however, to ensure that both the 2 - digit and 4 - digit manaufacturer code tokens are available on the POS system since they differ depending on the number of digits in the manufacturer code of the meter.
Meter specific management tokens (Class 2)
The meter specific management tokens are used to set parameters in the payment meter, as well as perform keychange operations on the payment meter.
Reserved tokens (Class 3)
This token class is reserved by the STS Association and must not be used in payment meters, or generated by the POS.
References: IEC62055-41 Ed2