Alstom MiCOM P846, Technical Manual

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P846/EN FD/D Firmware Design
(FD) 9-4
MiCOM P846
1.2.1 Real-time operating system
The real time operating system is used to provide a framework for the different parts of the
relay’s software to operate within. To this end the software is split into tasks.
The real-time operating system is responsible for scheduling the processing of these tasks
such that they are carried out in the time available and in the desired order of priority. The
operating system is also responsible for the exchange of information between tasks, in the
form of messages.
Main processor board
Relay
board
Power supply
board
Transformer board
Input board
Parallel data bus
Battery
backed-up
SRAM
Non-volatile
memory
SRAM
Flash
EPROM
CPU
Front LCD panel RS232 Front comms port
Parallel test port
LEDs
Digital inputs
Output relay contacts
ADC
Present values
of all
settings
CPU code & data,
setting database
data
Default settings &
parameters, language text,
software code
IRIG-B signal
Fibre optic
rear comms
port optional
Alarm, event, fault &
maintenance
records
Output relays
Opto-isolated
Analogue input signals
Power supply (3 voltages),
rear comms data
Digital input values
Power supply, rear comms
data, output relay status
Timing data
IRIG-B board
(optional)
Comms between
main & coprocessor
boards
CPU code
& data
FPGA
CPU
SRAM
Coprocessor board
Serial data bus (sample data)
inputs
(x16 or x24)
(x24 or x32)
FD
Current & voltage inputs (6 to 8)
Power
supply
Rear RS485
communication port
Watchdog
contacts
Field
voltage P1038ENC
P1038ENa
P1038ENa
Figure 1: Relay modules and information flow