Elster A1120, Руководство пользователя

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20
A1120/40 - Electronic Polyphase Meter
©
Elster Metering Limited - M181 001 2G - 5/2010
13 SECURITY FEATURES
Password Protection
The A1120/40 meter uses a Password as part of the security algorithm. The passwords must be
entered in upper case. Password protection can be disabled at manufacture if required.
Four levels of access are available.
Entering the correct password for levels 0, 1, 2 and 3 allows the functions in Figure 9 to be
performed, higher levels giving access to the lower levels. Passwords may also be set to defaults
using the Power Master Unit.
It is important to note that the integrity of the A1120/40 meter passwords should always be
protected. This can be achieved by ensuring the ability to change passwords is controlled and only
made available to Administrative Personnel.
The level 3 password should be changed at regular intervals. It may be appropriate for no more
than 100 meters to be protected by the same level 3 password.
Calibration values, zeroing of registers etc. are protected by a security link that is removed at the
factory before the meter is sealed.
13.1 Data Retention
All cumulative register and time of use data is saved to non-volatile memory every time the power
to the meter fails and also every 2 hours. The data is recovered when power is restored to the
meter.
All data is retained for the nominal life of the meter.
13.2 Recordable Security Features
The following security features are available and can be included in the display sequence:
13.2.1 Phase Present/Phase Fail Indication
The meter detects and stores the number of phase fail events to a maximum of 65535.
The register will then roll over to 0. A time and date stamp of the three most recent events is
recorded. The phase fail threshold can be set between 0 and 250 V.
Phase indication on the display (L1, L2, L3) has the following options:
Indicator ‘on’ when phase present
Indicator ‘on’ when phase failed
Where a meter is to be used on a supply with less than 4 wires, it is possible to disable the
monitoring and display of phases L2 and L3.
13.2.2 Reverse Energy Flow
Reverse run event count
The meter detects and stores the number of reverse running events to a maximum of 65535. The
register will then roll over to 0.
A time and date stamp of the three most recent events is recorded.