Second Rear Comms And Intermicom Board (Optional); Ethernet Or Redundant Ethernet Board (Optional); 9-2 Ethernet Board (Optional); Real-Time Operating System - GE MiCOM P40 Agile Technical Manual

Firmware Design
MiCOM P40 Agile P442, P444
1.1.7

Second rear comms and InterMiCOM board (optional)

The optional second rear port is designed typically for dial-up modem access by protection
engineers/operators, when the main port is reserved for SCADA traffic. It is denoted "SK4".
Communication is via one of three physical links: K-Bus, EIA(RS)485 or EIA(RS)232. The
port supports full local or remote protection and control access by MiCOM S1 Agile software.
The second rear port is also available with an on board IRIG-B input.
The optional board also houses port "SK5", the InterMiCOM teleprotection port. InterMiCOM
permits end-to-end signalling with a remote P440 relay, for example in a distance protection
channel aided scheme. Port SK5 has an EIA(RS)232 connection, allowing connection to a
MODEM, or compatible multiplexers.
1.1.8

Ethernet or Redundant Ethernet board (optional)

Ethernet or dual Ethernet boards are mandatory boards for IEC 61850 enabled relays. The
boards provide network connectivity through either copper or fibre media at rates of 10 Mb/s
or 100 Mb/s. There is also an option on the Ethernet board to specify IRIG-B board port
(modulated or un-modulated). These boards and the second rear comms board are mutually
exclusive as they both utilise slot A within the relay case.
The Redundant Ethernet board (see Px4x/EN REB user guide) option provides a redundant
connection, useful to safe exchanges between two relays or for specific network
applications. The different options use Self Healing Protocol (SHP), Rapid Spanning Tree
Protocol (RSTP) or Dual Homing Protocol (DHP).
All modules are connected by a parallel data and address bus that allows the processor
board to send and receive information to and from the other modules as required. There is
also a separate serial data bus for conveying sample data from the input module to the
processor.
Note:
1.1.9

9-2 Ethernet board (optional)

The 9-2 Ethernet board assures appropriate communication to IEC 61850-9-2LE (Lite
Edition) compliant Merging Units (MU).
The 9-2 Ethernet board is the communication interface between MiCOM protection and the
network. It replaces the conventional analogue inputs (analogue module) wherever it/they
stand (see Px4x/EN 9-2 user guide).
1.2 Software overview
The software for the relay can be conceptually split into four elements: the real-time
operating system, the system services software, the platform software and the protection
and control software. These four elements are not distinguishable to the user, and are all
processed by the same processor board. The distinction between the four parts of the
software is made purely for the purpose of explanation here:
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.
1.2.2 System services software
The system services software provides the low-level control of the relay hardware. For
example, the system services software controls the boot of the relay's software from the non-
It is possible to connect to the Ethernet network any of the P44x without the
embedded Ethernet board using the RS485 to Ethernet converter MiCOM I4X
(Courier protocol)
P44x/EN FD/Hb6
(FD) 8-7