Internal Clock; Local Time; Security; Access Control - Honeywell AS302P Operating Instructions Manual

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26. INTERNAL CLOCK

The AS302P compares its Time with the Comms Hub and adjusts as necessary. No event is recorded, providing the
time difference is no greater than 10s.
If the Time Difference is greater than 10s then the meter does not adjust its time but generates an Event in the Security
Log and sends an Alert over the HAN.
The Clock can also be changed by a 'Set Clock Command' (this can only occur once in a 24hr period). The meter
compares its Time with the Comms Hub and providing the Time is within the Validity Window then the Time will be
aligned to the Comms Hub. This will create an Event in the Event Log. If the Time is outside the Validity Window then
an Event is stored in Security Log and an Alert is raised.
When the Time is changed (by Adjust or Command) then the meter ensures it has not missed any required actions.
The Clock uses the notation 00:00 to 23:59. The Calendar automatically caters for Leap Years.
Note: - For Time Stamps 00:00 indicates the start of the day and 23:59 the end of the day.
The Time Base for the clock is derived from a Crystal Controlled Oscillator.
Crystal Calibration achieves an internal accuracy of better than 0.5 of a second per day at reference temperature. In
the event of a Supply Failure a Backup Battery supports the Crystal Oscillator.
In the absence of Mains Voltage the meter maintains Date and Time for a period exceeding two years. The Internal
Clock meets the requirements of BS EN 62054-21.

26.1. Local Time

The meter display shows Local Time.
The meter provides 2 Daylight Savings Dates whereby the Clock can be adjusted by one hour at the start of the summer
and can be restored at the end of the summer.

27. SECURITY

27.1. Access Control

The meter supports a number of different Role Based Access Levels, as defined in GBCS. These are:
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Supplier – Critical
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Supplier – Non-Critical
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Supplier – Top Up
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Network Operator – Critical
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Network Operator – Non-Critical
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Access Control Broker – Non-Critical
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Security, Transitional Change of Supplier – Critical
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Public (DLMS Mandatory)
If the Old Supplier requires any information from the meter, then this must be obtained through the Access Control Broker.
The meter will check the following items before executing a Command:
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Authenticity of any Command
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The Sender of the Command is authorised to do so
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The Integrity of the Command, which includes:
- The Structure of the Command (MAC Header, Group Header, Signature etc.)
- The Command Payload:
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© Honeywell - M450 001 1D - 23.05.2019
Where Constants are Defined, they are correct
Where a Range is Defined, they are within the boundaries
For Tariff, check if all Component Parts are included
For Prepayment, check that it is in the Correct Mode
Operating & Maintenance Instructions
43