Power Supply Loss; Internal And External Communications Module Power Supply; Using The Display; Figure 8: Meter Display In 'Test Mode - Secure Liberty 100 Technical Reference Manual

3.2.3 Power Supply Loss

When the supply voltage drops below the guaranteed metrology voltage the meter will switch to battery mode.
When this happens the meters microcontroller sends a supply loss signal to the communications module so that
a 'last gasp' (supply loss) message can be sent (if configured).
A last gasp message will only be sent if the meter is configured to do so and if optional backup power supply is
fitted. Multiple mains power outage within a 10 minutes window could affect the meters ability to send a 'last
gasp' message.

3.2.4 Internal and External Communications Module Power Supply

For internal (intimate) and external communications module the meter will provide a power supply of 4 V, 1.4 A.

3.3 Using the Display

Liberty 100 uses a custom LCD display which supports a ten (10) character, alphanumeric starburst display
along with icons for other relevant information. The height of the main characters is 7mm. The figure below
shows the illuminated segments during Display Test.

Figure 8: Meter display in 'Test Mode'

The meter is programmed to display information relating to its current mode of operation. The display list
comprises two types of display - Auto Scroll and Manual Mode. Auto Scroll is the default display mode which
automatically cycles through a configured display list.
Auto Scroll Mode
The Auto Scroll Mode displays information specific to the meter's current mode of operation. Prepayment, credit
and default modes will have different display sequences and sets of displayed parameters. At the end of a
complete sequence the display enters 'sleep mode' (turns blank) and returns to the first display when key 'B' is
pressed. The meter will suspend its Auto Scroll display when a message relating to supply restoration is to be
displayed.
Manual Mode
Manual Mode is entered by pressing a numeric key on the meter keypad. In this mode sets of information
relating to a function are grouped together on each numeric key. Pressing a key interrupts the Auto Scroll mode
and triggers the display to cycle through the configured set of parameters. Repeated pressing of the same key
manually jumps the display through the configured display list. Pressing key 'B' manually allows the displays to
go backwards.
A user can still view manual mode displays by means of the keypad when a supply restoration message is
displayed. If there is no user interaction after the last parameter is displayed, the meter displays a set of
parameters relating to its mode of operation before going into sleep mode. The supply restoration message will
be redisplayed only after any key is pressed on the meter keypad.
Page 14 of 116 Liberty 100 Smart Electricity Meter Technical Reference Manual BGX501-767-R02