Landis & Gyr Cashpower Gemini HMI User Manual - 11.3 Alarms
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Meter Operation (Energy Limiting Mode)
© Landis+Gyr (Pty) Ltd
Cashpower Gemini HMI
– User Guide
When operating in the energy limiting mode, the meter functions as follows:
The default display shows the amount of accumulated energy currently available.
Because the accumulation of energy takes place at 15-second intervals, the
amount incremented each time is very small e.g. 0.000870kWh.
With a normal meter display resolution of 0.1kWh, it will be some time before there is a
significant change that actually results in the displayed digits changing. The 15-second
changes can be viewed in real time with a resolution of 0.000001kWh via information register
063
– refer to section 13.31).
NB. When in information mode, the scrolling credit wedge is not displayed.
All other display icons work as per the prepayment mode of operation.(refer to section 9).
The load switch will remain in the closed position unless the meter is tampered,
decommissioned, in a power limit lockout state or if the DAE has been exceeded.
If the DAE is exceeded, the load switch will operate in exactly the same way as it
does when the meter is in power limiting mode. Also note that during the periods
that the load is disconnected (for either power limiting or DAE expired), the DAE
continues to increment in the background.
11.3 Alarms
The unique functionality of the energy limiting mode of operation requires a variation in the handling of
the low credit level alarm thresholds. Because credit levels are automatically incremented, it is
possible for the meter to move in and out of the alarm threshold without user interaction.
Another variation is the functioning of set credit level settings. In the energy limiting mode of operation
they are not treated as absolute values but interpreted as a percentage of the DAE. This in order to
prevent the resetting of alarm levels if and when the DAE values are adjusted. This setting is fixed at
the time of manufacture but can be changed via an engineering token at any stage.
The alarm functionality is implemented as follows:
A level of hysteresis is applied to the alarm settings such that it is activated at half of the low
credit level setting but only deactivates once it passes back up through the low credit level
setting. When in the alarm state, the buzzer sounds and the alert LED is flashed.
The audible alarm may be silenced by pressing any key on the keypad (the alarm LED will
continue to flash). It will remain silenced until such time as the credit level has passed back
through the low credit level. At this point the alarm LED turns off and, if the remaining credit
level is again decremented to below half of the low credit level, the above alarm sequence will
again be activated.
If the customer does not press a key on the keypad to silence the alarm as described above,
the buzzer will continue to sound and the alert LED flashed while the credit level is
Meter display format in
energy limiting mode with
credit decreasing
Scrolling direction
Scrolling direction
Meter display format in
energy limiting mode with
credit increasing