FIELD OF THE INVENTION
The present invention relates to an automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESPs) for air pollution control in manufacturing plant and also in ESP site during commissioning and maintenance.
BACKGROUND OF THE INVENTION
Electrostatic precipitators (ESP) electrically charge and collect particulates generated in industrial processes such as those generated in power plants, cement plants, and paper mills. Each field of an ESP consists of a collecting and emitting electrode pair with the collecting electrodes maintained negative polarity and the emitting electrode at positive polarity typically. The field is electrically energized by applying high voltage between positive and negative electrodes using a high voltage power supply system. The applied voltage produces high electric field including electrostatic forces between the electrodes, which ionizes and charges dust particles when made to pass between the electrodes, and the dust particles are collected in the surface of the electrodes with opposite polarity. Each of the fields of ESP needs to be individually controlled and monitored by a micro-controller based controller. The controllers are tested prior to commissioning the ESP and further, during maintenance of the ESP to ensure healthiness.

According to the known procedures, electrostatic precipitator controllers are tested for its functionality with desktop simulators, which simulate the field conditions. Simulators simulate field signals for example, current, voltage signals and alarm conditions using conventional analog and digital circuits. However, the known processes are prone to human errors and demand continuous human intervention including operator's skill and judgment.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose an automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESPs) for air pollution control in manufacturing plant which allows testing of various hardware components of the ESP controllers for example, input/output lines and communication channels.
Another object of the invention is to propose an automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESPs) for air pollution control in manufacturing plant which provides improved test results and reduced testing time.
A still another object of the invention is to propose an automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESPs) for air pollution control in manufacturing plant which is capable to provide a comprehensive test report after each test with specific error messages to initiate immediate remedial actions.

A further object of the invention is to propose an automated self-testing device for testing of micro-controller of electrostatic precipitators (ESPs)for air pollution control in manufacturing plant which provides an optional communication channel to transfer the test report to a host computer for documentation purpose.
SUMMARY OF THE INVENTION
According to the invention, an external dongle hardware is connected to the controller to conduct the test. The controller runs a self test of its hardware components like input/output lines, communication channels and identifies if there is a component/connection error.
The controller also generates a real-time comprehensive test report after the self test and provides the information to the users through the controller display screen. The real time data enables the users to quickly troubleshoot and rectify the errors, if any.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - shows a block diagram of an automated self-testing device for testing of micro-controllers of electrostatic precipitators according to the invention; connected to the controller under test.

DETAILED DESCRIPTION OF THE INVENTION
As shown in figure 1, the self test system comprises a self test device [1] and an electrostatic precipitator controller [2] under test. The electrostatic precipitator [2] comprises of a display module [3]; a digital output module [4] with 0 and 5V levels to drive relays for On/Off controls and provide gate control of the pair of thyristors connected back to back with a step-up transformer and rectifier that feeds power to the electrostatic precipitator; a digital input module [5] with 0 and 5V levels which read the various field status inputs like the warning and trip alarms; an analog input module [6] that reads 0-5V signals and indicates the values of electrostatic precipitator current and voltage; a first communication module [7] and a second communication module [8] interfaced with a central monitoring and control system. The self test device comprises a self test dongle with a plurality of links [9] between the digital input and digital output modules (4,5); a plurality of links [10] between the analog input and digital output modules (6,4); a communication link [11] between the serial communication channels (7,8) of the controller (2); a Power supply reference [12] for the analog input module (6); and an External serial communication link [13] from the dongle (1).
The self test dongle [1] is connected to the Electrostatic Precipitator controller (2) in place of the field connector so that all inputs [5, 6]/output [4] and serial communication channels [7, 8] are available for the test.

The dongle [1] loops back [9,10,11] the input [5,6]/output lines [4] and the communication channels [7,8] within the connector terminals. It also provides reference signals [12] for testing the analog input [6] lines.
The controller [2] identifies the presence of the dongle [1] when it is connected in place of the field connector. The controller [2] initiates a test cycle that generates several test conditions. The controller [2] also monitors the output links [9,10,11] from the dongle [1] at each test stage and compares it with the expected output. Multiple tests are performed involving the same input/output channel [7,8] and using the combinations of outputs the exact error condition is identified. Test conditions cover different types of errors in all input different types of errors in all input [5,6], the output [4] and the communication channels [7,8] of the controller [2] hardware. The self test cycle is completed within a few seconds.
The results of various test stages are retained in a memory of the testing device, and at the end of the entire test cycle; test report are generated and displayed on the controller display [3]. The dongle [1] has the link [13] to transfer the test reports to a host computer.

WE CLAIM:
1. An automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESP) used for air pollution control in manufacturing plant, comprising :
- a self test dongle (1) connectable to at least one micro controller (2) of the ESP having a display module (3);
- a first plurality of links (9) provided between the digital input and output modules (4, 5);
- a second plurality of links (10) provided between the analog input module (6) and the digital output module (6,4);
- a communication link (11) arranged between the serial communication channels (7,8) of the controller (2);
- a power supply reference signal (12) generated by the self test device (6); and
- an external serial communication link (13) provided between the dongle and a host computer;

wherein the dongle (1) loops back the input, output and communication links (9,10,11) including the input and output module (4,5,6) and the communication channels (7,8) and generate the reference signals (12) for testing the analog input/output [6] lines; wherein the controller (2) detects the connectivity of the dongle to initiate the test cycle with multiple tests on the same channel and uses the combination of results to identify the exact error condition, generates a test report specifying the location of the error and wherein the external serial communication interface (13) transmits the test reports to the host computer.
2. An automated self-testing device for testing of micro-controllers of electrostatic precipitators (ESPs) for air pollution control in manufacturing plant substantially as herein described and illustrated with reference to the accompanying drawings.

The invention relates to an automated self-testing device for testing of microcontrollers of electrostatic precipitators (ESPs) used for air pollution control in manufacturing plant comprising a self-test dongle (l)connectable to at least one micro-controller (2) of the ESP having a display module (3); a set up transformer and rectifier supplying power to the ESP connectable to a pair of thyristors, the thyristors being provided with on/off and gate control vial a plurality of relays driven by a digital output module (4) providing thyristor gate control for the ESP power supply and issuing warning and trip alarm signals; a digital input module
(5) providing the on-line values of the field status input; an analog input module
(6) indicating the voltage and current values of the ESP; a first and a second communication module (7,8) interfacing to a central monitoring and control system; a first plurality of links (9) provided between the digital input and output modules (4,5); a second plurality of links (10) provided between the analog input module (6) and the digital output module (6,4); a communication link (11) arranged between the serial communication channels (7,8) of the controller 2; a