GE P24DM, Technical Manual

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4 PLATFORM SOFTWARE
The platform software has three main functions:
● To control the logging of records generated by the protection software, including alarms, events, faults, and
maintenance records
●
To store and maintain a database of all of the settings in non-volatile memory
● To provide the internal interface between the settings database and the user interfaces, using the front
panel interface and the front and rear communication ports
4.1 RECORD LOGGING
The logging function is used to store all alarms, events, faults and maintenance records. The records are stored in
non-volatile memory to provide a log of what has happened. The IED maintains four types of log on a first in first
out basis (FIFO). These are:
● Alarms
●
Event records
● Fault records
●
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. The platform software is responsible for logging a maintenance
record in the event of an IED failure. This includes errors that have been detected by the platform software itself or
errors that are detected by either the system services or the protection software function. See the Monitoring and
Control chapter for further details on record logging.
4.2 SETTINGS DATABASE
The settings database contains all the settings and data, which are stored in non-volatile memory. The platform
software manages the settings database and ensures that only one user interface can modify the settings at any
one time. This is a necessary restriction to avoid conflict between different parts of the software during a setting
change.
Changes to protection settings and disturbance recorder settings, are first written to a temporary location SRAM
memory. This is sometimes called 'Scratchpad' memory. These settings are not written into non-volatile memory
immediately. This is because a batch of such changes should not be activated one by one, but as part of a
complete scheme. Once the complete scheme has been stored in SRAM, the batch of settings can be committed to
the non-volatile memory where they will become active.
4.3 INTERFACES
The settings and measurements database must be accessible from all of the interfaces to allow read and modify
operations. The platform software presents the data in the appropriate format for each of the interfaces (LCD
display, keypad and all the communications interfaces).
P24xM Chapter 4 - Software Design
P24xM-TM-EN-2.1 49