UM1524 Datasheet, PDF (19/35 Pages) STMicroelectronics – This document describes the functions

UM1524
Single-phase energy meter features
Note:
6.4.4
When the pushbutton SW3 is released, the LCD display returns to auto-scroll mode after a
pushbutton mode interval (10sec).
A pushbutton mode interval (8sec) is configurable in “pushbutton_display.h” in the firmware.
Meter low-power mode display
In low-power mode, display is off till pushbutton SW3 is pressed. When pushbutton SW3 is
pressed in low-power mode, display is on in auto-scroll display mode. The display is active
till pushbutton SW3 is in the pressed condition.
6.5
6.5.1
6.5.2
Note:
Tamper detection
The STEVAL-IPE012V2 demonstration board supports multiple tamper detection and their
logging in EEPROM.
Tamper types
The five types of tamper detection are:
● Earth tamper
● Reverse tamper
● Neutral missing tamper
● Case tamper
● Magnetic interference.
LCD symbol for tamper condition
● Earth tamper:
● Reverse tamper:
● Neutral missing tamper:
● Case tamper:
● Magnetic interference:
Three of the above tampers (earth, reverse and neutral missing) are detected using a
software algorithm based on meter readings from the metering IC.
In the case of neutral missing tamper detection, the board starts recording energy when the
load current is 2 A or higher.
Case tamper is detected using switch SW2 and magnetic interference is detected using
magnetic sensor U4. Symbol 'BP' is shared for displaying case tamper as well as magnetic
interference. It means if any of the tampers are detected, symbol 'BP' is displayed on the
LCD.
For tamper definitions, refer to Appendix B.
In the present solution, magnetic tamper is not logged in EEPROM. For logging, it can be
easily done by modifying the EEPROM log structure.
Doc ID 022901 Rev 1
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