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6.12.1. Magnetic field detection
The meter is equipped with a sensor that detects external magnetic fields. This type of field is typically applied to
the meter in an attempt (a magnetic attack) to defraud the utility company by disturbing the measurement
metrology sensors.
Note: The magnetic field of optical heads used for reading the meter are not detected by the sensor.
Operation
When the sensor detects a magnetic field:
• a non-fatal, trapped alarm is raised
Note: The alarm type is self-healing in earlier plateforms of SL7K.
• all serial communications via the RS232 or RS485 ports is suspended immediately
This occurs even if the magnetic detection feature is disabled or a communication session was in progress.
For the duration of the magnetic attack:
• the meter increments specific energy registers once every second. These registers:
• accumulate their respective energy type
• are only reset when they reach maximum value (not at EOB)
• do not have their values stored in any historical buffer registers at EOB
• all other registers continue to operate normally
At the end of the magnetic attack:
• a time stamped magnetic attack event is stored in the meter logbook
• all serial communication functions are restored
6.13. Alarm and event management
6.13.1. Logbook
The meter is factory programmed with a list of pre-defined metering Events. Using the meter support tool, events
from the list can be selected so that if they occur, a time-stamped record is made in the meter Logbook.
Then, whenever necessary, an analysis of meter behaviour can be made by investigating the logbook contents.
The logbook has a maximum capacity of 500 recorded events. Therefore, to ensure the logbook doesn't become
full too quickly, it is recommended that only events related to the installation requirements and the metering
context are selected, for example:
• specific action events
• communication events
• fatal and non-fatal alarm events (appearance and disappearance)
• asynchronous events
The selection of all other events should be carefully considered with regard to logbook capacity, for example:
If the event Periodical EOI is selected with a period equal to 15 minutes, then 96 Periodical EOI events will be
recorded each day, filling the logbook in about 5 days.
An integrated functional element called the Event Manager controls and manages all metered events.
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