Alstom MiCOM P546 - 3. RELAY SOFTWARE; 3.1 Real-time operating system; 3.2 System services software

P54x/EN FD/La4 Firmware Design
(FD) 9-14
MiCOM P543, P544, P545 & P546
3. RELAY SOFTWARE
The software can be considered to be made up of four sections:
 The real-time operating system
 The system services software
 The platform software
 The protection & control software
This section describes in detail the latter two of these, the platform software and the
protection & control software, which between them control the functional behavior of the
relay. Figure 6 shows the structure of the relay software.
Fourier signal
Fault locator
task
Disturbance
processing
Protection
algorithms
Programmable &
fixed scheme logic
Supervisor task
Protection
Co-processor
current differential
algorithms
recorder task
task
Measurements and event, fault
System services software
Relay hardware
Event, fault,
disturbance,
maintenance record
logging
Front panel
interface - LCD &
keypad
Settings
database
Remote
communications
interface -
IEC60870-5-103
Platform Software
Protection & control settings
Sample data & digital
logic inputs
Control of interfaces to keypad, LCD,
LEDs, front
& rear comms por
ts.
Self-checking maintenance records
Sampling function -
copies samples into
2 cycle buffer
Remote
communications
interface - Modbus
Local & Remote
communications
interface - Courier
Control of output contacts and
programmable LEDs
Protection & Control
Software
& disturbance records
P1040ENa
P1040ENa
FD
Figure 6 Relay software structure
3.1 Real-time operating system
The
software is split into tasks; the real-time operating system is used to schedule the
processing of the tasks to ensure that they are processed in the time available and in the
desired order of priority. The operating system is also responsible in part for controlling the
communication between the software tasks through the use of operating system messages.
3.2 System services software
As sh
own in Figure 5, the system services software provide
s the interface between the
relay’s hardware and the higher-level functionality of the platform software and the protection
& control software. For example, the system services software provides drivers for items
such as the LCD display, the keypad and the remote communication ports, and controls the
boot of the processor and downloading of the processor code into SRAM from flash EPROM
at power up.