F0RM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention: A SYSTEM AND A METHOD TO ENABLE/ DISABLE FACTORY SET FIXED PROTECTION SETTINGS USING SIMULATION KIT
2. Applicant(s):

(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian Company
(c) ADDRESS : L & T House, Ballard Estate, Mumbai
400 001, State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The present invention relates to circuit breaker and related accessories. Particularly, the present invention relates to electronic system where a settings needs to be toggled during normal operation depending on the nature of source or supply. More particularly the present invention relates to a system and a method to alter the state of factory set fixed protections which are not accessible to change easily. The said invention uses a simulation kit to access the settings fixed in the firmware and toggle it as per the need of the system.
BACKGROUND OF THE INVENTION AND PRIOR ART
Some protections offered by Electronic trip units are inherently fixed at some settings. On field depending on the nature of source or supply voltage there is a need to alter these settings. Traditional approach uses the two state switches. But these switches are bulky and take space in the front slot. Also these switches add to cost. Conventionally two wire communication methods are used for interfacing simulation kit and electronic trip unit. These communication methods add overhead firmware. Also intelligence needs to be added in simulation kit that adds up the cost.
EP 1230741 A4 discloses data communication over single wire through passive device. Here state of the pin (High

or low) is used for data representation. We claim to use the state of the port pin to toggle the setting of the said protection.
OBJECTS OF THE INVENTION
One object of the present invention is to overcome the disadvantages / drawbacks of the prior art.
A basic object of the present invention is to provide a system to alter the state of factory set fixed protections using simulation kit.
A basic object of the present invention is. to provide a system to alter fixed protection settings that is common to all trip units.
Another object of the present invention is to provide a method to alter the settings using simulation Kit.
Another object of the present invention is to enable digitally fixed protection.
Another object of the present invention is to disable digitally fixed protection.
These and other advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
According to one of the aspect of the present invention the system is provided a method to Enable / Disable Digitally fixed protection, said method comprising steps of:
storing of protection state in a non volatile memory means of a microcontroller;
sensing by means of said microcontroller the state of protection from a non volatile memory means;
checking of said state of protection adapted to decide whether to check for fault or not to check for fault;
wherein said protection state is checked and if it is disabled the said microcontroller does not issue trip even when fault is detected and if the state is enabled said microcontroller issues trip if fault is detected.

According to another aspect of the present invention there is provided a system to alter the fixed protection settings using simulation Kit., said system comprising:
a simulation kit, said kit comprises :
an input pin;
a Vcc means;
a ground means;
a reset means;
a micro controller operatively connected with said simulation kit;
a non-volatile memory means;
wherein said microcontroller and said input pin is connected to toggle the state of the protection .
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not

intended to limit the scope of the invention. The
drawings are not to scale (unless so stated) and are
intended for use in conjunction with the explanations in
the following detailed description.
Figure 1 illustrates Firmware flowchart for checking the
state of protection.
Figure 2 illustrates Firmware flowchart for toggling the
state of protection
Figure 3 illustrates the Block Diagram of connection
between Electronic trip unit and Simulation Kit.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a system and a method to Enable / Disable Digitally fixed protection settings using simulation kit

The simulation kit is connected to the electronic trip unit. The microcontroller in the trip unit monitors the state of an input pin. The input pin is made low by the Simulation kit. The microcontroller detects this input pin low and monitors it for a predefined time to ensure that it is low. The monitoring for a predefined time is done to avoid any nuisance being detected as low on input. After the low is detected, the state of protection is toggled. This state is then written in non volatile memory. After the procedure is completed, the simulation kit is disconnected.
At power up, it checks the state of the protection. After reading from non volatile memory the state of protection, Enable/disable state to be considered is decided. Then the protection proceeds with its algorithm.
Communication between simulation kit and microcontroller to toggle the state of protection is achieved using only one I/O line of the microcontroller.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: Firmware flowchart for checking the state of
protection.
a) In step 1, the state of protection is read from Non volatile Memory (NVM). The state of protection decides whether Enable or disable to be considered before issuing a trip.

b) In step 2, the state of protection is checked.
c) If the state of protection is 'DISABLE', the system does not check for fault. (Step 4). If the state is 'ENABLE', system checks for fault (Step 3).
d) If the fault condition is detected, the system issues a trip command.
Figure 2: Firmware flowchart for toggling the state of
protection
When the Simulation kit 2 is connected to the Electronic trip unit 1, following procedure is done:
a) In step 1, it is checked whether an input pin at microcontroller 1 is pulled low by the Simulation kit 2 for a predefined time.
b) If a yes is detected for condition mentioned in step 1, the interrupts are disabled (Step 2), LED is made continuously on, to show that the protection state is being changed, (Step 3) . After completing this, the state of the protection is toggled (Step 4).
c) In step 5, the protection state is stored in non volatile memory (NVM).
d) After writing to NVM, the data written to it is verified in step 6, 7.

e) If valid data is written in NVM, the LED starts blinking healthy (Step 9), Interrupts are enabled (Step 10) and program exits the loop.
f) If valid data is not written to NVM, then LED is made OFF to indicate error in writing. (Step 8)
g) If in step 1, the input is not made low for the given amount of time then the step 9 and 10 are directly executed.
Figure 3: Block Diagram of connection between Electronic trip unit and Simulation Kit.
The figure shows the connections between Simulation kit 2 and Electronic Trip unit 1. The Simulation kit 2 provides Vcc, ground reset and an input pin to Electronic trip unit 1. The input pin is made low for predefined time to toggle the state of protection. When the input pin is made LOW, the microcontroller detects the condition. After the condition is detected, microcontroller 1 checks whether the input is low for predefined time and then takes necessary action.

Advantages:
• Only single I/O line used for
communication between microcontroller and simulation kit.
• Factory set fixed protections can be
disabled if the need be.

WE CLAIM:
1. A method to Enable factory set fixed protection ,
said method comprising steps of:
storing of protection state in a non volatile memory means of a microcontroller;
sensing by means of said microcontroller the state of protection from a non volatile memory means;
checking of said state of protection adapted to decide whether to check for fault or not to check for fault;
wherein said protection state is checked and if it is disabled the said microcontroller does not issue trip even when fault is detected and if the state is enabled said microcontroller issues trip if fault is detected.
2. A method to Disable factory set fixed protection,
said method comprising steps of:
storing of protection state in a non volatile memory means of a microcontroller;
sensing by means of said microcontroller the state of protection from a non volatile memory means;
checking of said state of protection adapted to decide whether to check for fault or not to check for fault;

wherein said protection state is checked and if it is disabled the said microcontroller does not issue trip even when fault is detected and if the state is enabled said microcontroller issues trip if fault is detected.
3. Method as claimed in claim 1 or 2 comprising verification of stored protection state data.
4. A system to Enable factory set fixed protection ,
said system comprising:
a simulation kit, said kit comprises : an input pin; a Vcc means; a ground means; a reset means;
a microcontroller means operatively connected with
said simulation kit;
a non-volatile memory means;
wherein said microcontroller means and said input pin is connected to toggle the state of protection .
5. A system to Disable factory set fixed protection ,
said system comprising:
a simulation kit, said kit comprises :

an input pin;
a Vcc means;
a ground means;
a reset means;
a microcontroller means operatively connected with said simulation kit;
a non-volatile memory means;
wherein said microcontroller means and said input pin is connected to toggle the state of protection .
6. System as claimed in claim 4 or 5 wherein said input pin is made low by the said simulation kit.
7. System as claimed in claim 4 or 5 wherein the microcontroller detects the input pin low.
8. System as claimed in claim 4 or 5 or 6 wherein the microcontroller monitors the input pin low for some time to avoid any nuisance being detected as low on input.
9. System as claimed in claim 4 or 5 wherein the protection data stored in the non volatile memory is being verified.

10. System as claimed in claim 4 or 5 further comprising a single I/O line for communication between electronic trip unit and simulation kit.
11. A method to Enable/Disable factory set fixed protections as herein described and illustrated with reference to the accompanying drawings.
12. A system to enable/disable factory set fixed protections as herein described and illustrated with reference to the accompanying drawings.