Sofware Design Overview; Figure 27: Software Architecture - GE P4A Technical Manual

Chapter 4 - Software Design
2

SOFWARE DESIGN OVERVIEW

The device software can be conceptually categorized into several elements as follows:
The system level software
●
The platform software
●
● The protection and control software
These elements are not distinguishable to the user, and the distinction is made purely for the purposes of
explanation. The following figure shows the software architecture.
Programmable & fixed
scheme logic
Signal processing
Sampling function
Sample data + digital
logic inputs
System services (e.g. device drivers) / Real time operating system / Self-diagnostic software
V00307

Figure 27: Software Architecture

The software, which executes on the main processor, can be divided into a number of functions as illustrated
above. Each function is further broken down into a number of separate tasks. These tasks are then run according
to a scheduler. They are run at either a fixed rate or they are event driven. The tasks communicate with each other
as and when required.
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Protection and Control Software Layer
Protection Task
Coprocessor protection
algorithms
Protection algorithms
Supervisor task
Control of output contacts
and programmable LEDs
System Level Software Layer
Hardware Device Layer
LEDs / LCD / Keypad / Memory / FPGA
Fault locator
task
Platform Software Layer
Event, fault,
disturbance,
Settings database
maintenance record
logging
Front panel
interface
(LCD + Keypad)
Control of interfaces to keypad , LCD, LEDs,
front & rear ports.
Self-checking maintenance records
P54A/B/C/E
Disturbance
recorder task
Remote
communications
interfaces
Local
communications
interfaces
P54xMED-TM-EN-1