TOKEN TYPES
In the STS domain a token can be defined as a message containing data to be sent to a payment meter via several possible carrier types. The following token types are defined in the IEC62055-41 specification:
Credit tokens (Class 0)
Unit based tokens transfer utility units in the following categories:
| Token Type | Sub-class | Utility Units |
| Electricity credit | 0 | 0.1 kilowatt-hours |
| Water Credit | 1 | 0.1 cubic meters |
| Gas Credit | 2 | 0.1 cubic meters |
| Time Credit | 3 | 0.1 minutes |
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, therefore 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)
|
Token Type |
Sub-Class |
Value/control |
|
Test token (2-digit man code) |
0 |
varies depending on test selected |
|
Test Token (4-digit man code) |
1 |
varies depending on test selected |
|
Extended token read |
2 |
0 – 63 |
|
Proprietary tokens |
6 – 15 |
Not defined |
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 manufacturer code tokens are available on the POS system since they differ depending on the number of digits in the manufacturer code of the meter.
Non meter specific management tokens (Class 1)
The meter specific management tokens are used to set parameters in the payment meter, as well as perform key-change operations on the payment meter. These tokens include:
- Key-change tokens – Tokens used to update the decryption key in the meter.
- Maximum Power limit tokens – Tokens used to change the maximum power that the meter may supply.
- Clear Credit tokens – Tokens used to clear the existing credit in the meter.
- Maximum Phase Power Unbalance Limit tokens – Tokens used to set the maximum unbalance between phases
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