Record Logging; Settings Database; Database Interface; Protection And Control Software - GE MiCOM P40 Agile Technical Manual

Firmware Design
MiCOM P40 Agile P442, P444
3.3 Platform software
The platform software has three main functions:
• To control the logging of records that are generated by the protection software,
including alarms and event, fault, and maintenance records.
• To store and maintain a database of all of the relay's settings in non-volatile memory.
• To provide the internal interface between the settings database and each of the relay's
user interfaces, i.e. the front panel interface and the front and rear communication
ports, using whichever communication protocol has been specified (Courier, Modbus,
IEC 60870-5-103, DNP3).
3.3.1

Record logging

The logging function is provided to store all alarms, events, faults and maintenance records.
The records for all of these incidents are logged in battery backed-up SRAM in order to
provide a non-volatile log of what has happened. The relay maintains four logs: one each for
up to 96 alarms (with 64 application alarms: 32 alarms in alarm status 1 and another group
of 32 alarms in alarm status 2 and 32 alarms platform (see GC annex for mapping), 250
event records, 5 fault records and 5 maintenance records. The logs are maintained such that
the oldest record is overwritten with the newest record. The logging function can be initiated
from the protection software or the platform software is responsible for logging of a
maintenance record in the event of a relay failure. This includes errors that have been
detected by the platform software itself or error that are detected by either the system
services or the protection software function. See also the section on supervision and
diagnostics later in this section.
3.3.2

Settings database

The settings database contains all of the settings and data for the relay, including the
protection, disturbance recorder and control & support settings. The settings are maintained
in non-volatile E2PROM memory. The platform software's management of the settings
database includes the responsibility of ensuring that only one user interface modifies the
settings of the database at any one time. This feature is employed to avoid conflict between
different parts of the software during a setting change. For changes to protection settings
and disturbance recorder settings, the platform software operates a 'scratchpad' in SRAM
memory. This allows a number of setting changes to be applied to the protection elements,
disturbance recorder and saved in the database in E2PROM. (See § 3, section P44x/EN IT).
If a setting change affects the protection & control task, the database advises it of the new
values.
3.3.3

Database interface

The other function of the platform software is to implement the relay's internal interface
between the database and each of the relay's user interfaces. The database of settings and
measurements must be accessible from all of the relay's user interfaces to allow read and
modify operations. The platform software presents the data in the appropriate format for
each user interface.
3.4

Protection and control software

The protection and control software task is responsible for processing all of the protection
elements and measurement functions of the relay. To achieve this it has to communicate
with both the system services software and the platform software as well as organise its own
operations. The protection software has the highest priority of any of the software tasks in
the relay in order to provide the fastest possible protection response. The protection &
control software has a supervisor task which controls the start-up of the task and deals with
the exchange of messages between the task and the platform software.
P44x/EN FD/Hb6
(FD) 8-17