FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
An improved communication system in RTU
APPLICANT(S):
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai -400 030, Maharashtra, India, an Indian Company.
INVENTOR(S):
Malviya Ashish of Crompton Greaves Limited, DARC (Distribution Automation Research Centre), Aryabhatta, Global R&D Centre, Kanjurmarg (East), Mumbai -400 042, Maharashtra, India; an Indian National.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
The invention relates to the field of communication systems and information systems for real time embedded products / systems.
Particularly, this invention relates to communication systems between a remote terminal unit and a remotely located processing means.
Specifically, this invention relates to an improved communication system in RTU.
BACKGROUND OF THE INVENTION:
In the field of remote telemetry, an on-site equipment is monitored and sensed by a remote terminal unit (RTU). Typically, a RTU provides for automatic transmission and measurement of data to remotely located processing means via serial or Ethernet link.
This processing means may be a SCADA (supervisory control and data acquisition) means. This processing means is the master station. There may be a plurality of master stations which receive information and data from various RTUs. The RTUs are the slave stations and may receive signals from the master station in order to control on-site equipment or to poll the RTUs.
CG Automation System's XCell Real Time System (RTS) provides an RTU (Remote Terminal Unit) platform that is industry standard protocol conversion, I/O data gathering, and control and automation functionality. XCell Processor Module (CPR-041) combines I/O processing, communications (4 - RS232 / RS422 / RS485 Serial Port, 1-TCP/IP Port), user configuration, diagnostics and applications

programming. Each XCell processor has the capability to process up to 256 I/Os. CGAS Workbench™ is one system that integrates a Configuration Development Tool, an On-Line Monitoring and Diagnostics Utility mechanism for RTU and a Firmware Flash Programming Utility mechanism. XCell RTU (Remote Terminal Unit) hardware has flexible and scalable architecture with a real-time operating system.
IEC60870-5-101/104 are companion protocol standards generated for basic telecontrol tasks (supervisory control and data acquisition) in electrical engineering and power system automation applications. IEC 60870-5-104 (IEC 104) protocol is an extension of IEC101 protocol with the changes in transport, network, link and physical layer services to suit the complete network access. Application layer of IEC 104 is preserved same as that of IEC101 with some of the data types and facilities not used. For the purposes of this specification, IEC-60870-5-101/104 Master station is referred to as a IEC Master or a master station while IEC-60870-5-101/104 Slave is referred to as a IEC Slave or a slave station.
There is a need such that multiple IEC Master Stations can monitor and control the XCell IEC Slave(s) by using one serial or Ethernet communication link.
In the system of the prior art, there is a slave station on XCell RTU, such that one IEC Slave station can communicate with one IEC Master station at a time but not more than one, over single serial or Ethernet link, as shown in figure 1 of the accompanying drawings. But, there is a need for Multiple IEC Master station connections with single (or multiple) IEC slave stations of XCell RTU, over single

serial or Ethernet link, in order to increase reliability of the system and also to provide cost effective solution for redundancy at multiple IEC Master stations.
According to the prior art, there is single entry in IEC101 Gen table for serial port. It also restricts the usability of IEC101 Slave stations on remaining 3 serial ports by IEC101 Masters.
Therefore,
1. More than one IEC 104 Master or IEC 101 Master station cannot communicate simultaneously with IEC 104 or IEC101 Slave station over single serial or Ethernet link of XCell;
2. To implement Multiple Master scenerio, the system needs separate XCell hardware, which is not a cost effective solution; and
3. Limited usability of IEC101 Slave stations on remaining 3 serial ports of CPR-041.
PRIOR ART:
Prior art literature relating to "SCADALink IP 100: Modbus Mux / Modbus Serial TCP Gateway / SCADA Terminal Server" discloses simultaneous multi-ports for hosting multi connections to provide a redundant connection through a serial or Ethernet interface and configured to combine both the Modbus IP and Serial Mux mode by sharing a Single Serial Port of PLC RTU modbus slave. However, it does not provide a solution for routing multiple TCP/IP entries for creating multiple simultaneous connections.
Prior art literature relating to "SCADALink IP Gateway: Modbus Mutliplexer

(Mux) / Multiport Modbus Ethernet Gateway" discloses a Modbus Multiplexer mode that enables multiple Modbus Masters to communicate to a single Modbus Slave. However, it does not provide a solution for routing multiple TCP/IP entries for creating multiple simultaneous connections.
Prior art patent document US2008104614 discloses plurality of master devices communicating with the single physical device using only the single slave address. However, the single slave addresses have multiple virtual slaves.
However, none of the above prior art documents, in combination or in whole, teach, suggest, or motivate eliminating redundancy at multiple master stations over serial links or Ethernet links.
OBJECTS OF THE INVENTION:
An object of the invention is to provide a cost effective solution for redundancy at multiple IEC master stations.
Another object of the invention is to provide a system which uses serial ports as well as Ethernet ports simultaneously for communication between slave stations and master stations.
Yet another object of the invention is to provide a system which uses serial ports as well as Ethernet ports simultaneously for communication between slave stations and master stations, without the addition of hardware.
Still another object of the invention is to eliminate software redundancy.

An additional object of the invention is to eliminate hardware redundancy.
SUMMARY OF THE INVENTION:
According to this invention, there is provided an improved communication system-in RTU adapted to provide communication architecture and protocol between at least an input/output card to at least a master station through at least a slave station, said system comprises:
a. slave data handling means adapted to handle input data from a at least an
input/output card, said slave data handling means further comprising at least
an Ethernet port and at least a serial port for communication to said at least a
master station, said slave data handling means adapted to segregate input data
and route it to respective said at least an Ethernet port or respective said at
least a serial port in relation to pre-defined parameters; and
b. at least a first master station adapted to receive data from said slave data
handling means through communication determined with said at least an
Ethernet port and at least a second master station adapted to receive data from
said slave data handling means through communication determined with said
at least a serial port.
Typically, said slave data handling means comprising a plurality of serial ports adapted to receive segregated and routed data.
Typically, said slave data handling means comprising a plurality of sockets of Ethernet port adapted to receive segregated and routed data.

Typically, said slave data handling means comprising at least a serial application task handling means adapted to route data through said at least a serial port.
Typically, said slave data handling means comprising bundles or groups of serial application task handling means which are parallel placed, each of said bundles or groups of sad serial application task handling means connecting and routing information to pre-defined serial ports.
Typically, said slave data handling means comprising bundles or groups of serial application task handling means adapted to use a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each instance, poll table functions are run and corresponding master station request is subsequently processed.
Typically, said slave data handling means comprising a plurality of serial queue handling means adapted to queue and manage data from each of said bundles or groups of serial application task handling means in relation to pre-defined configuration or priority of handling data before being routed to corresponding serial ports.
Typically, said slave data handling means comprising a plurality of Ethernet application task handling means adapted to route data through an Ethernet port.
Typically, said slave data handling means comprising at least an Ethernet application task handling means adapted to use a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each

instance, poll table functions are run and corresponding master station request is subsequently processed.
Typically, said slave data handling means comprising at least an Ethernet queue handling means adapted to queue and manage data from said plurality of Ethernet application task handling means in relation to pre-defined configuration or priority of handling data before being routed to the corresponding TCP/IP sockets.
Typically, said slave data handling means comprising a plurality of serial receive task handling means adapted to receive queued data from a corresponding serial queue handling means before being routed or transmitted to a corresponding serial port.
Typically, said slave data handling means comprising a plurality of serial receive task handling means adapted to receive data from at least a corresponding master station from an Serial port and further adapted to send message to a Logical RTU task for processing, thereby enabling multiple link address entries for one serial port for creating multiple simultaneous connections with corresponding master stations and hence, creating multiple entries for serial ports for creating multiple corresponding master station connections over corresponding serial links.
Typically, said slave data handling means comprising at least an Ethernet receive task handling means adapted to receive queued data from a corresponding Ethernet queue handling means before being routed or transmitted to the Ethernet port.
Typically, said slave data handling means comprising at least an Ethernet receive task handling means adapted to receive data from at least a corresponding master

station from a corresponding Ethernet socket and fiirther adapted to send message to a Logical RTU (LRU) task for processing, thereby enabling multiple TCP/IP entries for creating multiple simultaneous connections with corresponding master stations over single Ethernet link.
Typically, said slave data handling means comprising a server task handling means adapted to creates a server socket and listen for clients' connections, said server task handling means being connected to an Ethernet receive task handling means through a server task queue such that single server task handles all TCP/IP socket connections (Ethernet port connections) to keep live all sockets or to resolve sockets timeout issue.
Typically, said system includes a control system adapted to allow entry of multiple link address and serial ports in order to simultaneously achieve both soft and hard redundancy.
Typically, said slave data handling means is located at a remote telemetry unit adapted to receive on-site or field equipment data.
Typically, said slave data handling means comprising handling means for at least an Ethernet port and at least a serial port, thereby enabling a dual-combination means
Typically, said slave data handling means comprising a control system for incoming data to be tagged with header or pointer information relating to Ethernet port or Serial Port through which it is to be transmitted.

Typically, said system comprising a series of master stations to form a bundle of group of master stations and further forming such groups or bundles to be placed in parallel in order to receive data from each of said at least a serial port and / or said at least an Ethernet port (EP) in a parallel fashion / manner.
Typically, said system comprising a physical Ethernet link adapted to form a communication channel between said at least an Ethernet port at said corresponding at least a master station.
Typically, said system comprising a physical serial link adapted to form a communication channel between said at least a serial port at said corresponding at least a master station.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure la illustrates a communication system wherein communication between input/output card through a slave station and a master station is via an Ethernet port and an Ethernet link; and
Figure lb illustrates a communication system wherein communication between input/output card through a slave station and a master station is via a serial port and a serial link.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a schematic block diagram of the system.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure la illustrates a communication system wherein communication between input/output card through a slave station and a master station is via an Ethernet port and an Ethernet link.
Data from input/output cards (IOC) is received by a card and mapped into IEC slave (IEC-S), running on Real-Time Operating System (RTOS) based Processor Unit. Data is handled by a single Ethernet application task handling means (ETH) adapted to route data through a single Ethernet port (EP). A physical Ethernet layer (PEL) links Ethernet port (EP) to a single master station (MS). An Ethernet queue handling means (EQHM) is adapted to queue and manage data from Ethernet application task handling means (ETH) before being routed to the corresponding Ethernet port (EP) through Ethernet receive task handling means (ERT).
Figure lb illustrates a communication system wherein communication between input/output card through a slave station and a master station is via a serial port and a serial link.
Data from input/output cards (IOC) is received by a card and mapped into IEC slave (IEC-S), running on Real-Time Operating System (RTOS) based Processor Unit. Data is handled by a single serial application task handling means (STH) adapted to route data through a single serial port (SP). A physical serial layer (PSL) links serial port (SP) to a single master station (MS). An serial queue handling means (SQHM) is adapted to queue and manage data from serial application task handling means (STH) before being routed to the corresponding serial port (SP) through serial receive task handling means (SRT).

According to this invention, there is provided an improved communication system in RTU adapted to provide communication architecture and protocol between at least an input/output card to at least a master station through at least a slave station.
Figure 2 illustrates a schematic block diagram of the system.
In accordance with an embodiment of this invention, there is provided a slave data handling means (SDH) adapted to handle incoming or input data from a plurality of input / output cards (IOC). Typically, the slave data handling means is located at a remote telemetry unit adapted to receive on-site or field equipment data. The slave data handling means, in accordance with this invention, comprises handling means for at least an Ethernet port and at least a serial port. A dual-combination means is enabled by the slave data handling means of this invention. Incoming data may be tagged with header or pointer information relating to Ethernet port or Serial Port through which it is to be transmitted. The slave data handling means handles the incoming data to segregate it and route it to the respective Ethernet port or the respective serial port.
According to an exemplary embodiment, 4 serial ports (SRI, SR2, SR3, SR4) are illustrated which receive segregated and routed data from the slave data handling means. Also, 1 Ethernet port (EP) is illustrated which receives segregated and routed data from the slave data handling means.
The slave data handling means (SDH) comprises a plurality of serial application task handling means (STH1, STH2, STHn) adapted to route data through serial ports (SRI, SR2, SR3, SR4). Bundles or groups of serial application task handling means (STH1, STH2, STHn) can be parallel placed. Each bundle of group of the

serial application task handling means (STH1, STH2, STHn) connects and routes information to a pre-defined serial port (SRI, SR2, SR3, SR4). The serial application task handling means (STH1, STH2, STHn) uses a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each instance, poll table functions are run and corresponding master station request is subsequently processed.
The slave data handling means (SDH) further comprises a plurality of serial queue handling means (SQHM) adapted to queue and manage data from each of the bundles or groups of serial application task handling means (STH1, STH2, STHn) in relation to pre-defined configuration or priority of handling data before being routed to the corresponding serial ports (SRI, SR2, SR3, SR4).
The slave data handling means (SDH) still further comprises a plurality of Ethernet application task handling means (ETH1, ETH2, ETHn) adapted to route data through an Ethernet port (EP). The Ethernet application task handling means (ETH1, ETH2, ETHn) uses a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each instance, poll table functions are run and corresponding master station request is subsequently processed.
The slave data handling means (SDH) further comprises an Ethernet queue handling means (EQHM) adapted to queue and manage data from the plurality of Ethernet application task handling means (ETH1, ETH2, ETHn) in relation to predefined configuration or priority of handling data before being routed to the corresponding Ethernet ports (EP).

The slave data handling means (SDH) still further comprises a plurality of serial receive task handling means (SRT) adapted to receive queued data from a corresponding serial queue handling means (SQHM) before being routed or transmitted to a corresponding serial port (SP1, SP2, SP3, SP4). It receives data from corresponding master stations from a port and sends message to a Logical RTU (LRU) task for processing. Hence, multiple link address entries for one serial port can be formed for creating multiple simultaneous connections with corresponding master stations. Hence, multiple entries for serial ports can be formed for creating multiple corresponding master station connections.
The slave data handling means (SDH) still further comprises an Ethernet receive task handling means (ERT) adapted to receive queued data from a corresponding Ethernet queue handling means (EQHM) before being routed or transmitted to the Ethernet port (EP). It receives data from corresponding master stations from a socket and sends message to a Logical RTU (LRU) task for processing. Hence, multiple TCP/IP entries in can be formed for creating multiple simultaneous connections with corresponding master stations over single Ethernet link.
It gives cost effective solution and increases reliability of the system.
The slave data handling means (SDH) still further comprises a server task handling means (STH). It creates a server socket and listens for clients' connections. It is connected to the Ethernet receive task handling means (ERT) through a server task queue (STQ). Single server task handles all TCP/IP socket connections (Ethernet port connections) to keep live all sockets or to resolve sockets timeout issue. This occurs when huge data points are mapped in slave data handling means and more

master station connections with the slave data handling means are formed, due to sequential data polling method of master station.
In accordance with an embodiment of this invention, there is provided a series of master stations (MSl,...,MSn) adapted to receive data from the serial data handling means (SDH). Each of the series of master stations (MSl,...,MSn) form a bundle of group of master stations and many such groups or bundles are placed in parallel in order to receive data from each of the serial ports (SP1, SP2, SP3, SP4) and / or the Ethernet port (EP) in a parallel fashion / manner. The communication of data from the Ethernet Port (EP) of the slave data handling means (SDH) to the master stations (MSl,...,MSn) is through a physical Ethernet link (PEL). The communication of data from each of the serial ports (SP1, SP2, SP3, SP4) of the slave data handling means (SDH) to the corresponding master stations (MSl,...,MSn) is through a physical Serial link (PSL).
By entering, multiple link address and serial ports in a control system, both soft and hard redundancy can be achieved simultaneously.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. An improved communication system in RTU, adapted to provide
communication architecture and protocol between at least an input/output
card to at least a master station through at least a slave station, said system
comprising:
a. slave data handling means adapted to handle input data from a at least an
input/output card, said slave data handling means further comprising at
least an Ethernet port and at least a serial port for communication to said
at least a master station, said slave data handling means adapted to
segregate input data and route it to respective said at least an Ethernet
port or respective said at least a serial port in relation to pre-defined
parameters; and
b. at least a first master station adapted to receive data from said slave data
handling means through communication determined with said at least an
Ethernet port and at least a second master station adapted to receive data
from said slave data handling means through communication determined
with said at least a serial port.
2. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of serial ports adapted to receive segregated and routed data.
3. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of sockets of Ethernet port adapted to receive segregated and routed data.

4. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising at least a serial application task handling means adapted to route data through said at least a serial port.
5. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising bundles or groups of serial application task handling means which are parallel placed, each of said bundles or groups of said serial application task handling means connecting and routing information to pre-defined serial ports.
6. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising bundles or groups of serial application task handling means adapted to use a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each instance, poll table functions are run and corresponding master station request is subsequently processed.
7. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of serial queue handling means adapted to queue and manage data from each of said bundles or groups of serial application task handling means in relation to pre-defined configuration or priority of handling data before being routed to corresponding serial ports.
8. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of Ethernet application task handling means adapted to route data through an Ethernet port.

9. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising at least an Ethernet application task handling means adapted to use a methodology wherein, for each record of data to be routed, a Logical RTU (LRU) instance is created and for each instance, poll table functions are run and corresponding master station request is subsequently processed.
10. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising at least an Ethernet queue handling means adapted to queue and manage data from said plurality of Ethernet application task handling means in relation to pre-defined configuration or priority of handling data before being routed to the corresponding TCP/IP sockets.
11. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of serial receive task handling means adapted to receive queued data from a corresponding serial queue handling means before being routed or transmitted to a corresponding serial port.
12. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a plurality of serial receive task handling means adapted to receive data from at least a corresponding master station from an Serial port and further adapted to send message to a Logical RTU task for processing, thereby enabling multiple link address entries for one serial port for creating multiple simultaneous connections with corresponding master stations and hence, creating multiple entries for serial

ports for creating multiple corresponding master station connections over corresponding serial links.
13. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising at least an Ethernet receive task handling means adapted to receive queued data from a corresponding Ethernet queue handling means before being routed or transmitted to the Ethernet port.
14. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising at least an Ethernet receive task handling means adapted to receive data from at least a corresponding master station from a corresponding Ethernet port socket and further adapted to send message to a Logical RTU (LRU) task for processing, thereby enabling multiple TCP/IP entries for creating multiple simultaneous connections with corresponding master stations over single Ethernet link.
15. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a server task handling means adapted to creates a server socket and listen for clients' connections, said server task handling means being connected to an Ethernet receive task handling means through a server task queue such that single server task handles all TCP/IP socket connections (Ethernet port connections) to keep live all sockets or to resolve sockets timeout issue.
16. An improved communication system as claimed in claim 1 wherein, said system includes a control system adapted to allow entry of multiple link

address and serial ports in order to simultaneously achieve both soft and hard redundancy.
17. An improved communication system as claimed in claim 1 wherein, said slave data handling means is located at a remote telemetry unit adapted to receive on-site or field equipment data.
18. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising handling means for at least an Ethernet port and at least a serial port, thereby enabling a dual-combination means
19. An improved communication system as claimed in claim 1 wherein, said slave data handling means comprising a control system for incoming data to be tagged with header or pointer information relating to Ethernet port or Serial Port through which it is to be transmitted.
20. An improved communication system as claimed in claim 1 wherein, said system comprising a series of master stations to form a bundle of group of master stations and further forming such groups or bundles to be placed in parallel in order to receive data from each of said at least a serial port and / or said at least an Ethernet port (EP) in a parallel fashion / manner.
21. An improved communication system as claimed in claim 1 wherein, said system comprising a physical Ethernet link adapted to form a communication channel between said at least an Ethernet port at said corresponding at least a master station.

22. An improved communication system as claimed in claim 1 wherein, said system comprising a physical serial link adapted to form a communication channel between said at least a serial port at said corresponding at least a master station.