Landis & Gyr Cashpower Gemini PLC User manual - page 30
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Customer Interface Unit Operation
© Landis+Gyr (Pty) Ltd
Cashpower Gemini PLC
– User Guide
Whenever the customer interface unit is disconnected from the mains supply, it continues to operate
for another 30 seconds, at which point it stores the last known meter status before entering into
power-save mode to conserve battery energy. When in the power-save mode, the customer interface
unit is completely switched off and there is no display or background activity. It may be woken up at
any stage by pressing and holding the information key on the keypad for a period of 3 seconds.
On „waking up‟, it will display the last known meter status. If the display indicates a zero credit
condition and the load switch status as open, it is clear that the meter is out of credit and a new credit
voucher will have to be entered in order to restore power. If, however, the display shows the load
switch in the closed position and some amount of credit still available, it can be safely assumed that
there is a general power failure.
Having „woken up‟ and displayed the information as indicated above, the customer interface unit
automatically proceeds to interrogate the meter for an updated status. Depending on the prevailing
status, this will result in any one of the following responses:
If there has been any change in the meter status, it will be reflected on the display.
If there is a general power failure, the meter will not be able to respond i.e. there will be no
communication possible with it. Under these conditions, the customer interface unit will
evaluate the last known status of the meter load switch and do one of the following:
If the load switch indicates closed, it will assume a power failure, retain the existing display
information and enter into power-save mode after 30 seconds.
If the load switch indicates open, it will display the communications error (30) after 30 seconds
and shut down again. Note that this will now be the default display whenever the customer
interface unit is again „woken up‟. It will only be cleared once AC power has been restored and
communication with the meter re-established.
In the absence of any further key-presses, the customer interface unit will enter into the power-
save mode again after 30 seconds.
A credit voucher may be entered under battery power in the normal way, after the customer interface
unit has been „woken up‟ as described above.
Refer to
– 10.3 for details of the battery condition indicator.