The magnetic cards have a unique code on them, which is only recognised by our meters.
When the card is inserted in the meter, the magnetic code is read. If the code matches our meter code, then the credit is added to the meter and the card is erased. The card is also clipped to show it has been used. The cards are disposible and cannot be used again.
When the CARDmeter has credit on it, then a connection is made between the input terminals and the output terminals of the meter, and so the load receives power.
The electrical consumption is continiously measured and decrements the credit displayed on the meter. When the credit runs out, the connection between the input and output terminals is broken and so the power to the load removed.
When the first meter is supplied, and programming card is included with the order. When this is inserted in the CARDmeter, it unlocks the programming menu. Here is is possible to set the pence per unit (ppu), which is the same as pence per kWh.
It is also possible to set a standing charge, which is input as a weekly rate. Every 1/100 of a week (1.63hrs), the credit is reduced by 1/100th of the weeksly standing charge rate set.