Description:A SYSTEM TO MONITOR AND CONTROL ELECTROSTATIC PRECIPITATOR FUNCTIONS USING REDUNDANT COMMUNICATION
FIELD OF INVENTION
[0001] The present disclosure relates to a monitoring and control system for electrostatic precipitator used for air pollution control. The invention particularly relates to a wireless network and a two-wire redundant network for monitoring and control of electrostatic precipitator.
BACKGROUND
[0002] Electrostatic precipitation is one of the most effective ways to control air pollution generated by industrial emissions. This technique, which has proven highly effective in controlling air pollution, has been used for removal of undesirable matter from a gas stream by electrostatic precipitation. Electrostatic precipitator (hereafter referred to as ESP) is an air pollution control device designed to electrically charge and collect particulates generated from industrial processes such as those occurring in power plants, cement plants, pulp and paper mills and utilities etc.
[0003] The electrically charged particles are attracted towards electrode plates, viz., discharge electrode and collection plate. ESP is divided into a plurality of fields depending on the dust load. A field is considered healthy as long as it is charged with sufficient voltage and current between its discharge and collection plate. During continuous operation of an electrostatic precipitator, the dust from the collector plates and the discharge electrodes must be periodically removed for further conveying of the collected dust. Dust collected on the electrodes is removed by periodically rapping/hitting the electrodes with mechanical hammers controlled by rapping motors.
[0004] The rapping mechanism is critical to ESP efficiency and so is controlled automatically by a dedicated controlled or by the ESP Power supply controller itself. The dust or ash is collected in the hoppers designated to individual fields. It is necessary to keep the hoppers at a particular temperature to avoid clinkering of ash particles. The hopper heaters keep the hoppers heated up and the thermostat controls the switching ON & OFF of the hopper heaters. The ash level indicators (ALI) are used to detect the level of ash inside the ESP hoppers.
[0005] In a conventional ESP control system, approximately 30km of control cables, its trays and supporting structures are routed from the ESP control room to ESP field. The approach of using wireless (ZigBee Pro) communication network along with a two-wire Controller Area Network (CAN) technology can reduce the cabling & associated costs without compromising on signal integrity & data latency. The above three functions namely, the ESP rapping system, hopper heater system and the system are being controlled and monitored by the ZigBee Pro (206 a) based wireless system for ESP with two-wire CAN protocol as redundancy.
[0006] In the prevailing practice, mechanism exists to integrate EC & HVR through signal cables such that signals like secondary voltage, secondary current and other sensor inputs are directly connected to EC through individual signal cables. For a typical power plant, the amount of cables required for such signal sensing runs into kilometers and thereby increased installation cost. Also, time taken to commission all these cables is very high.
[0007] There are some systems/methods known in the prior art showing some efforts on development of wireless communication for ESP Controllers. These are discussed in the following sections:
[0008] A Prior art 549/KOL/2008 relates to an improved method of communication between controllers and sensors for electrostatic precipitator. The invention is based on wireless communication between EC panel and EC-HVR is based on ZigBee protocol instead of ZigBee Pro. However, the invention requires the presence of coordinator for the network to sustain. A third party device may be required to monitor all the wireless devices.
[0009] Yet another prior art 431/KOL/2007 relates to ZigBee Wireless Technology Based Level Indicators for Power Plant Applications. The invention does not mention about the self-sustenance of the network in case of coordinator failure or even after a power cycle.
[0010] The drawbacks of conventional technology include the systems described in other prior arts do not provide redundancy in any form. There is no mention about co-existence of more than one mesh network in the same location in other prior arts.
[0011] Yet another drawback of the conventional technology does not describe on the self-sustenance of the network in case of coordinator failure or even after a power cycle and pairing mechanism. Thus there is a pressing need to achieve the same.
OBJECTS OF THE INVENTION
[0012] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0013] It is therefore an object of the present invention to provide a ZigBee Pro based wireless control system for ESP with reduced cabling & associated costs without compromising on signal integrity & data latency
[0014] Another object of the invention is to provide a method of pairing and functioning in the application layer on top of the ZigBee Pro stack to better suit the stringent requirements in our industrial application.
[0015] Yet another object of the invention is to provide a ZigBee Pro based wireless control system for ESP for the functions like rapping motor, hopper heater and thermostat and the ash level indication system wherein same hardware system can be configured to handle the different functions.
[0016] Yet another object of the invention is to provide a CAN protocol based two-wire control system as redundancy to the ZigBee Pro based wireless control system.
[0017] Yet another object of the invention is to provide a control system with both ZigBee Pro wireless protocol and CAN two-wire protocol suitable for industrial application with features as explained in the detailed description and claims.
[0018] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taking into consideration with accompanied drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION
[0019] This summary is provided to introduce concepts related to a system to monitor and control Electrostatic Precipitator functions using redundant communication. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. A system for interfacing signals between an ESP control panel and an ESP field using ZigBee Pro and CAN protocols by replacing cables running between them, the system comprises of a wireless mesh network based on the ZigBee Pro protocol consisting of a coordinator, routers and a repeater node with a unique security key, a cluster ID and end points and a redundant multi-master two-wire CAN communication interface.
[0020] In one aspect, the data sources and sink devices of the wireless mesh network are paired through broadcasts within the ZigBee Pro network.
[0021] In another aspect, the ZigBee Pro network transmits data from a source to a destination based on a pairing between the functional nodes which is attained through a user configurable setting.
[0022] In another aspect, the coordinator starts the ZigBee Pro network and provides a network ID and an Extended PAN ID that is configured to match with a boiler unit number, wherein the coordinator can be configured to switch off after the formation of the ZigBee Pro network, and wherein the addition of new nodes is independent of the coordinator.
[0023] In another aspect, a power disruption to the system does not affect allocation of the network IDs.
[0024] In another aspect, the ZigBee modules are made to function as a functional node, a repeater or a sniffer based on the allocation of DIP switches, wherein the ZigBee modules take up a different function when a PDM is deleted.
[0025] In another aspect, a sniffer node monitors status of all the nodes in the wireless mesh network, wherein the sniffer node receives a periodic data from all nodes and transmits the same to the ESP control panel.
[0026] In one aspect, the communication is allowed only between nodes with an extended PAN ID.
[0027] In another aspect, ZigBee module indicates multiple error condition /status of self or a paired device in the wireless mesh network.
[0028] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0029] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0030] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which
[0031] Fig. 1 illustrates the existing method of ESP control system.in accordance with an embodiment of the present disclosure;
[0032] Fig. 2 illustrates ZigBee Pro based wireless mesh network for an ESP control system.in accordance with an embodiment of the present disclosure;
[0033] Fig.3 illustrates a schematic diagram of CAN protocol based two-wire control system for an ESP in accordance with an embodiment of the present disclosure;
[0034] Fig. 4 illustrates a schematic diagram of the ZigBee Pro mesh network with RS 485 link between the ZigBee modules and the IBC & ORC in accordance with an embodiment of the present disclosure;
[0035] Fig. 5 illustrates a schematic diagram of the process of pairing among the router modules in accordance with an embodiment of the present disclosure;
[0036] Fig. 6 illustrates a schematic diagram of address setting hardware used in the ZigBee module with an embodiment of the present disclosure;
[0037] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0038] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
[0039] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0040] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0041] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0042] Various embodiments are further described herein with reference to the accompanying figures. It should be noted that the description and figures relate to exemplary embodiments and should not be construed as a limitation to the subject matter of the present disclosure. It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the subject matter of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the subject matter of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof. Yet further, for the sake of brevity, operation or working principles pertaining to the technical material that is known in the technical field of the present disclosure have not been described in detail so as not to unnecessarily obscure the present disclosure.
[0043] Fig. 1 illustrates the existing method of ESP control system.in accordance with an embodiment of the present disclosure. The existing method of ESP control system comprises of several runs of multicore control cables are run between the ESP control room (102) and the ESP field (104) for respective functions. The control cable for different applications are laid and run separately from the control to ESP. The method is to provide precise control over the ESP system and ensure that each component of the system is functioning as intended. The use of separate control cables for each application helps to minimize interference and ensure that the signals being sent are accurately received and processed.
[0044] However, this method can be complex and time-consuming to install and maintain, especially if there are a large number of cables running between the control room (102) and the ESP field (104). It may also require a significant amount of space for cable runs and may be prone to signal interference if not installed correctly.
[0045] Fig. 2 illustrates ZigBee Pro based wireless mesh network for an ESP control system.in accordance with an embodiment of the present disclosure. The system (100) for interfacing signals between an Electrostatic Precipitator, an ESP control panel and an ESP field (104) using ZigBee Pro and CAN protocols by replacing cables running between them, the system (100) comprises of a wireless mesh network based on the ZigBee Pro protocol consisting of a coordinator, routers and a repeater node with a unique security key, a cluster ID and end points; and a redundant multi-master two-wire CAN communication interface (5).
[0046] The preferred embodiment comprises of four major components. The first component is the ZigBee wireless module (1) which is developed on NXP’s JN5168-001-M06 single chip microcontroller. It includes a high power wireless system. The ZigBee module (1) can act as a coordinator, a router or a sniffer depending on the software program loaded in it. This allows for flexibility in how the system (100) is configured and how data is routed between different components. It also has RS485 interface for communication with Input buffer card (2) and Output Relay Card (3).
[0047] The field mounted Input buffer card[IBC] (2) is a 24 channel digital input card that has both RS485 and CAN interfaces. The control room mounted Output Relay card [ORC] (3) is a 24 channel digital output card that can drive up to 24 relays. It has both RS485 and CAN interfaces (5). The Wireless Junction Box (4) is designed for outdoor application with IP65 degree of protection. All the electronic components are placed inside these junction boxes in the ESP field (104)
[0048] In the preferred embodiment, the two-wire CAN communication interface (5) is enabled as redundant communication interface to achieve the higher reliability.
[0049] The system (100) is provided with a versatile ESP control system based on ZigBee Pro based protocol and redundant CAN based protocol. The system (100) as such is an improved method of interfacing signals between ESP control panel and ESP field (104) using ZigBee Pro and CAN protocols by replacing the cables running between them. All the wireless modules regain their previous state after a power cycle.
[0050] Fig.3 illustrates a schematic diagram of CAN protocol based two-wire control system for an ESP in accordance with an embodiment of the present disclosure. A wireless mesh network based on ZigBee Pro based protocol is a type of decentralized wireless network that uses a mesh topology to relay data between devices. The network is comprised of three types of devices: coordinator, routers, and end devices.
[0051] The coordinator is responsible for starting and managing the network. It is typically the most powerful device in the network and is used to set up the network, add and remove devices, and manage network traffic.
[0052] The routers are fully functional devices that act as intermediaries between end devices and the coordinator. They can transmit and receive data, and also act as repeaters for range extension, allowing the network to cover larger areas. Routers are classified into functional routers, repeaters, and sniffers.
[0053] Functional routers are the most basic type of router, responsible for relaying data between end devices and the coordinator. They are fully functional and can also act as repeaters.
[0054] Repeater routers are used to extend the range of the network by repeating signals from functional routers. They do not have any other functionality apart from relaying signals.
[0055] Sniffer routers are used for data concentration, monitoring, and troubleshooting. They collect data from other devices in the network and send it to the coordinator for analysis.
[0056] End devices are low-power devices that communicate with routers to transmit and receive data. They typically have limited functionality and are designed to conserve power, allowing them to run on battery power for extended periods.
[0057] The ZigBee Pro based protocol is used to ensure that all devices in the network are interoperable and can communicate with each other.
[0058] Fig. 4 illustrates a schematic diagram of the ZigBee Pro mesh network with RS 485 link between the ZigBee Pro and the IBC & ORC in accordance with an embodiment of the present disclosure. The wireless network as such is custom designed for a robust industrial application where the number of nodes are more and physical obstructions are many. Though the base protocol is ZigBee Pro, the system (100) is designed to work with a common cluster ID and End Point numbers for all the nodes in the network. The only differentiating factor between the nodes is the unique network ID. The data sources and sink devices of the wireless mesh network are paired through broadcasts within the ZigBee Pro protocol.
[0059] The ZigBee Pro network transmits data from a source to a destination based on a pairing between the functional nodes which is attained through a user configurable setting.
[0060] Further the coordinator starts the ZigBee Pro network and provides a network ID and an Extended PAN ID that is configured to match with a boiler unit number, wherein the coordinator can be configured to switch off after the formation of the ZigBee Pro network, and wherein the addition of new nodes is independent of the coordinator. A single ZigBee Pro mesh network is envisaged for one boiler unit. One network has a single coordinator which is responsible for starting the network. The unique security key does not allow external devices to join the network or decode any data that is transmitted. The extended PAN ID of the network depends on the boiler unit number which is read from the DIP switch setting by the software during run time.
[0061] The coordinator permits new routers to join the network and provides them with the network ID. All other modules are programmed as routers which are Fully Functional Devices. The routers can also parent a child, which means new routers can join the network and get their network ID through already joined routers. The routers are designated as functional nodes or repeaters or sniffer based on a user configurable setting (DIP switch in the hardware). The coordinator is not necessary once the network is formed. The network is self-sustaining and self-repairable.
[0062] The ZigBee Pro are designated function wise (rapping system including the collecting electrode rapping motor and the emitting electrode rapping motor, hopper heater system with thermostat and finally, the ash level indicating system) and ESP pass wise based on the DIP switches in the hardware. Based on the hardware, the ZigBee Pro are classified as Input buffer card modules or Output relay card modules or Repeaters. The ZigBee Module (1) connected to a particular IBC (2) has the same address setting as the IBC. This module is paired with another ZigBee Module (1) connected to ORC (3) which has the same address setting. Final data transfer takes place between an IBC (2) in the ESP field (104) and its pair ORC (3) in ESP control room (102).
[0063] Fig. 5 illustrates a schematic diagram of the process of pairing among the router modules in accordance with an embodiment of the present disclosure.
[0064] Further, the pairing process adopts a sequential procedure to identify the correct destination. The ZigBee module (1) on powering up checks whether it is configured as a sniffer or a repeater or a router. A sniffer configuration collects data from all wireless modules and sends data over RS485 line to a user interface system. A repeater configuration transfers data to the addressed nodes. A router configured module which comes up first sends a broadcast message to all the nodes in the network with its own network ID and DIP switch setting (CAN ID) as part of the broadcasted data every 20s and checks for receipt of similar broadcast messages from other unpaired routers. The DIP switch setting bits received in the broadcast message is checked for matching with respect to its own DIP switch setting and if matched, sends a unicast to the source with its own network ID at 10s intervals. If a corresponding unicast message is received from its pair device, an acknowledgment message is sent to its pair and the network IDs are permanently stored in the memory.
[0065] Once joined in the network, the routers retain their network ID even after resets unless the user chooses to delete the persistent data in the non-volatile memory (PDM delete), which again is settable through the DIP switch. Retaining the network ID helps the routers to start communicating immediately even after a power supply disruption. Any functional change if required can be achieved only after a PDM delete.
[0066] The functional nodes in the ESP field (104) are responsible for receiving data over RS 485 from the IBC (2) and transmitting the same over ZigBee to its destination. The destination node again receives data over wireless and transmits the same to ORC (3) over RS 485. Each functional node has its pair device as is its destination. Data is received and processed only after confirming the respective source address which is part of the received data. The reception of data at each level is confirmed through acknowledgements from the destination node or device. The functional nodes are placed inside the E1 or E3 junction boxes (4).
[0067] The ZigBee Module (1) designated as a Repeater is responsible only for relaying of data in the mesh network. They are used to improve the range or provide line of sight wherever necessary. They are placed inside the E2 junction boxes.
[0068] The ZigBee Module (1) designated as Sniffer is used to receive periodic data from all the nodes in the mesh network including coordinator and transmit the data to ESP Central Monitoring System over RS485. This helps in analyzing the complete network from a single point and to monitor the status of the modules. The Sniffer node can be placed anywhere in the ESP control room.
[0069] The system (100) is designed and programmed to communicate with nodes with same Extended PAN ID. This ensures that there no unwanted communication between nodes of other boiler units and mesh networks of several boiler units can coexist
[0070] The network IDs of paired devices are retained even after resets or power disruptions. If the network IDs were stored in volatile memory (memory that loses its contents when the power is turned off), the pairing would be lost after a power disruption or system reset. By storing the network IDs in NVM, the pairing between the devices can be retained even after power disruptions or resets. The PDM delete is perfumed to reset the router device's network ID or DIP switch setting. By performing a PDM delete, the user can reset the router device's network ID or DIP switch setting, effectively wiping out the previous pairing information and allowing the device to be reconfigured.
[0071] In the present embodiment if the router device experiences a power disruption or system reset, the stored network ID information is not lost due to the use of NVM. When the router device restarts, it will retain its previously assigned network ID, allowing it to immediately establish communication with its paired devices.
[0072] A power disruption or system reset can cause significant downtime and loss of productivity. By retaining its network ID even after resets or power disruptions, the router device can immediately resume communication with its paired devices, minimizing downtime and reducing the risk of lost productivity.
[0073] Further the PDM delete process is adjustable via the DIP switch on the router device. This means that the user can adjust the settings of the DIP switch to enable or disable the PDM delete process. By adjusting the DIP switch setting, the user can enable or disable the PDM delete process, allowing for greater flexibility and control over the configuration of the network.
[0074] Fig. 6 illustrates a schematic diagram of address setting hardware used in the ZigBee Module (1) with an embodiment of the present disclosure. The DIP switches are used for setting the address of the ZigBee Module (1). The DIP switch is read by the software and this decides the function of the ZigBee Module (1). The pass no. function, boiler unit no. programming mode and PDM delete mode all are decided by the DIP switch setting. SW1 is used to set the ESP pass no. for the module. SW2 setting will decide the function of the module as rapping motor, thermostat or the ash level indicator.SW3 will decide the boiler unit no. and SW4 is used for putting the module in programming mode and also for deleting the persistent data in the nonvolatile memory. The IBC and ORC use only SW1 and SW2 switches to specify the function and pass no.
[0075] The system (100) is designed and programmed to indicate the user regarding various error conditions/ status for easy troubleshooting. The following error / status conditions can be monitored from ESP control room (102) itself:
• Input buffer card (2) (IBC) not available
• Pair ZigBee Pro (1) at IBC (204) or ORC not available
• Output relay card (3) not available
• Coordinator not available
[0076] The system (100) as such is very unique in the run time allocation of addresses based on the hardware. The address allocation system is explained as per the table below
DIP SWITCH POSITIONS IN WIRELESS RELAY CARD AND WIRELESS BUFFER CARD FOR PASS NO:
PASS NO: SW1 - DIP SWITCH NO:
8 7 6 5
1 ON ON ON ON
2 ON ON ON OFF
3 ON ON OFF ON
4 ON ON OFF OFF
5 ON OFF ON ON
6 ON OFF ON OFF
7 ON OFF OFF ON
8 ON OFF OFF OFF
9 OFF ON ON ON
10 OFF ON ON OFF
11 OFF ON OFF ON
12 OFF ON OFF OFF
13 OFF OFF ON ON
14 OFF OFF ON OFF
15 OFF OFF OFF ON
16 OFF OFF OFF OFF

Table 1: DIP Switch Positions in Wireless Relay Card and Wireless Buffer Card Pass No
DIP SWITCH POSITIONS IN WIRELESS RELAY CARD AND WIRELESS BUFFER CARD FOR FUNCTION
FUNCTION SW2 - DIP SWITCH NO:
4 3 2 1
EERM MOTOR ON ON ON ON
CERM MOTOR ON ON ON OFF
ALI HIGH ON ON OFF ON
ALI MIDDLE ON ON OFF OFF
ALI LOW ON OFF ON ON
HOPPER HEATER ON OFF ON OFF
HI HEATER ON OFF OFF ON

Table 2: DIP switch positions in wireless relay card and wireless buffer card for function
The DIP switches of the ZIM modules.
DIP SWITCH POSITIONS IN ZIGBEE DONGLES FOR PASS NO:
PASS NO: SW1 - DIP SWITCH NO:
1 2 3 4
1 OFF OFF OFF OFF
2 OFF OFF OFF ON
3 OFF OFF ON OFF
4 OFF OFF ON ON
5 OFF ON OFF OFF
6 OFF ON OFF ON
7 OFF ON ON OFF
8 OFF ON ON ON
9 ON OFF OFF OFF
10 ON OFF OFF ON
11 ON OFF ON OFF
12 ON OFF ON ON
13 ON ON OFF OFF
14 ON ON OFF ON
15 ON ON ON OFF
16 ON ON ON ON

Table 3: DIP switch positions in ZIGBEE DONGLES for Pass No

DIP SWITCH POSITIONS IN ZIGBEE DONGLES FOR FUNCTION
FUNCTION SW2 - DIP SWITCH NO:
1 2 3 4
EERM MOTOR OFF OFF OFF OFF
CERM MOTOR OFF OFF OFF ON
ALI HIGH OFF OFF ON OFF
ALI MIDDLE OFF OFF ON ON
ALI LOW OFF ON OFF OFF
HOPPER HEATER OFF ON OFF ON
HI HEATER OFF ON ON OFF

Table 4: DIP switch positions in ZIGBEE DONGLES for Function

SW3 - DIP SWITCH NO: UNIT NO:
1 2 3 4
L-BUFFER CARD OFF OFF ON 1
OFF ON OFF 2
OFF ON ON 3
ON OFF OFF 4
H-RELAY CARD ON OFF ON 5
ON ON OFF 6
ON ON ON 7
Table 5: DIP switch positions in ZIGBEE DONGLES for Unit & card type
SW4
2 4
PROG MODE ON OFF
ROUTER OFF OFF
REPEATER OFF ON

Table 6: DIP switch positions in ZIGBEE DONGLES for Mode selection

[0077] In the preferred embodiment all the IBC (2) and ORC (3) in the redundant two-wire CAN system (5) are connected in a single CAN network (5). CAN is a multi-master network. The periodic data is transmitted from the IBC (2) in the ESP area to the corresponding ORC (3) in the ESP Control room (102). When the same data is received over both ZigBee (1) and CAN (5), the one which reaches first at the ORC (3) is processed and the other one is discarded based on the token number of the data frame.
[0078] In the preferred embodiment the input buffer card (2) receives the data for processing. Receiving data from the input buffer card (2) involves obtaining digital input data from input buffer card (2) in 24 channels. The input buffer card (2) is equipped with both RS485 and CAN interfaces (5), which allows for communication with external devices or systems.

ADVANTAGES

[0079] The proposed invention set aims to the following advantages over the conventional system:
• self-sustaining monitoring
• control system for ESP is based on redundant communication protocols.
• eliminates all the multicore control cables between control room and ESP.
• self-sustaining i.e. unaffected by the removal of the coordinator and also a power disruption.
• All the wireless modules regain their previous state after a power cycle.
• used for different router functions based on user settable DIP switch settings.
• self-reliant one with coordinator, fully functional routers, repeaters & sniffer.
• offers flexibility and various indications for hassle free operation.
• two-wire CAN network acts as a redundant system for higher reliability.
[0080] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0081] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0082] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0083] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
, Claims:We Claim:
1. A system for interfacing signals between an ESP control panel and an ESP field using ZigBee Pro and CAN protocols by replacing cables running between them, the system (100) comprising:
a wireless mesh network based on the ZigBee Pro protocol consisting of a coordinator, routers and a repeater node with a unique security key, a cluster ID and end points; and
a redundant multi-master two-wire CAN communication interface (5).
2. The system (100) as claimed in claim 1, wherein data sources and sink devices of the wireless mesh network are paired through broadcasts within the ZigBee Pro network.
3. The system (100) as claimed in claim 1, wherein the ZigBee Pro network transmits data from a source to a destination based on a pairing between the functional nodes which is attained through a user configurable setting.
4. The system (100) as claimed in claim 1, wherein the coordinator starts the ZigBee Pro network and provides a network ID and an Extended PAN ID that is configured to match with a boiler unit number, wherein the coordinator can be configured to switch off after the formation of the ZigBee Pro network, and wherein the addition of new nodes is independent of the coordinator.
5. The system (100) as claimed in claim 1, wherein a power disruption to the system (100) does not affect allocation of the network IDs.
6. The system (100) as claimed in claim 1, wherein the ZigBee modules (1) are made to function as a functional node, a repeater or a sniffer based on the allocation of DIP switches, wherein the ZigBee modules (1) take up a different function when a PDM is deleted.
7. The system (100) as claimed in claim 1, wherein a sniffer node monitors status of all the nodes in the wireless mesh network, wherein the sniffer node receives a periodic data from all nodes and transmits the same to the ESP control panel (102).
8. The system (100) as claimed in claim 4, wherein the communication is allowed only between nodes with an extended PAN ID.
9. The system (100) as claimed in claim 1, a ZigBee module indicates multiple error condition /status of self or a paired device in the wireless mesh network.