Patent Application
20070129814
This invention relates to the field of industrial controllers. More specifically, the invention relates to a programmable logic controller for use in buildings, industrial application or within machines for the control of industrial processes and machines.
Industrial controllers are special purpose computers used for controlling industrial processes and manufacturing equipment on a real-time basis. For example, industrial controllers are used to regulate room temperature, humidity, fans, lighting and other building automation functions. As illustrated in
A controller requires many functions provided by different components. First, the processor is usually provided on the main printed circuit board and executes the program. Input/output (I/O) ports are also provided to interface with equipment or probes. A power supply is further required to operate the controller. Optionally, a communication port, or bus interface, is provided for advanced communication with other controllers, for example.
The inputs and outputs are processed by I/O circuitry that performs any necessary data type conversion, level shifting, isolation and amplification of the signals to and from the processor so as to be compatible with the signals required by the industrial controller. Processor and I/O circuitry for industrial control are well known in the art.
Existing industrial controllers may be produced in which the processor and the necessary I/O circuits are contained within a single housing. For some applications such as when the controller is installed within a cabinet, it is desirable for the housing to have as small a base, or footprint, as possible to preserve cabinet space. Typically, a small footprint is accommodated by dividing the internal circuitry of the controller into multiple circuit cards stacked one on top of another. In addition to holding the processor and I/O circuits, the industrial controller must support terminal blocks or the like providing a means to connect the signals of the controlled equipment to the I/O circuitry. Two sets of terminal blocks are usually provided, one for input signals and one for output signals. The terminal blocks may also provide connections for line power in, user power out, and other signals known in the art. In the field of industrial controllers, terminal blocks are typically of the type using a screw to hold the wires. These types of terminal blocks are bulky, which adds to the size of the controller. Furthermore, this type of terminal requires much manual manipulation by an electrician or other installer adding cost to the process.
Typical industrial controllers require a power voltage that is different from the voltage of the electrical mains. Hence, a separate power supply is used to convert voltage from the electrical mains to the voltage required by the controller. The power supply is annexed to the controller, taking further space, which may be of concern when packaging the controller within a cabinet. Furthermore, the power supply needs to be connected to the power input terminal blocks of the controller, requiring additional wiring and manipulations.
The controller may further incorporate communication ports for remote control, networking with other controllers or remote diagnostic. Such communications are typically done using a standard communication protocol such as BACnet™ or Modbus™, for example.
It is customary, in the field of industrial controllers, to provide controllers pre-configured to address a specialized task as defined by the type and the number of inputs and outputs, such as reading temperature and controlling specific types of valves, vents and fan motors for an air-conditioning control application. Such a specialized controller comes with software drivers for the I/O devices, and leaves the high level program to a consultant to define, as illustrated in
Thus, when a customer has an application where he or she needs to control a piece of equipment, he consults a consultant of industrial control equipment, as illustrated in
Alternatively, it sometimes happens that the industrial controller manufacturer designs and builds a specific, complete turnkey control system for a customer. This process is illustrated in
This excessive level of customization in present industrial controllers is a real problem when a customer needs to modify his installation because, for example, he bought a new piece of equipment or if he simply desires to provide better efficiency by adding probes and/or controls. Presently, the customer is not capable of modifying the controller card of the industrial controller because it does not have the right input/output design. The customer therefore needs to buy a new controller or a new extension card.
Customization of the specific application controllers also creates a problem for product manufacturers integrating these controllers in their products. Indeed, each specific application controller is limited in its applications to the particular one application it was custom designed for. He therefore needs to ask for a controller designed specifically for a new application.
There is therefore a need to provide an industrial controller that combines the advantages of being generic in its design while being easily configurable for different applications, having all its functions integrated rather than necessitating many separate modules, being physically compact and being both quick and cheap to manufacture and install. There is a need to provide an industrial controller that does not require a high level of expertise to select, configure and install. An industrial controller that is user friendly and “plug and play” or turnkey is required.
It has been discovered that there is a need for an industrial controller that can be installed within the context of an existing industrial system having a predetermined expected physical installation. It has been discovered that by building a wiring harness especially for such existing industrial systems, the existing industrial systems can receive a control system having a controller and the special wire harness interconnecting probes or controls and displays or controlled devices to the controller. By having the specially designed harness matching the physical installation of the industrial system, namely a harness with predefined dimensions to efficiently allow I/O devices to be connected to the controller with the controller mounted in the physical installation, a technician can complete installation of the controller without having to hook-up the terminals.
The approach according to the invention differs from the prior art in that the installer uses an application-specific harness and an application specific controller program obtained from industrial controller suppliers with an essentially generic controller to install in the environment an industrial controller solution.
In this specification, “harness” is understood to mean a group of insulated electrical and/or optical fiber conductors that is bound together near a proximal end as a trunk and has at least two branches from the trunk and at least three terminations, each branch comprising a single conductor termination or a bound sub-group of conductors, for leading to different I/O device terminations at different expected installation positions within the expected industrial system.
In accordance with a first aspect of the present invention, there is provided a set of industrial controllers for controlling controlled devices. The set of industrial controllers comprises a plurality of common industrial controllers. Each industrial controller itself comprises at least one printed circuit board, a processor mounted on one printed circuit board and a power supply mounted on one printed circuit board. At least two of the industrial controllers comprise a first instruction set and a first harness, both corresponding to a first application. Similarly, at least two other of the industrial controllers comprise a second instruction set and a second harness corresponding to a second application. Notably, the first and second applications are different, the first and second instruction sets are different and the first and second harnesses are also different. Advantageously, the power supplies are capable of operating directly from electrical mains having a voltage comprised between 85 VAC and 265 VAC. Preferably, at least one of the industrial controllers is mounted within a standard electrical junction box. More preferably, the standard electrical junction box is of dimensions 4 11/16 inches by 4 11/16 inches.
In accordance with a second aspect of the present invention, there is provided a method for providing industrial controllers for controlling controlled devices. The method comprises the first step of a) defining a first and a second control applications where each control application involves a plurality of measurements or control inputs including at least one measurement input and a plurality of display or device outputs including at least one controlled device output for controlling an industrial system, process or machine in response to the inputs. Each control application further involves a predetermined expected physical installation of probes or controls providing the inputs, and of displays or controlled devices receiving the outputs. The method further comprise the next steps of b) providing a common industrial controller, c) defining a first and a second instruction sets corresponding respectively to the first and second control applications, d) providing a first and a second harnesses having dimensions and conductor types corresponding respectively to the first and second inputs, outputs and expected physical installations, e) supplying the industrial controller with the first instruction set and the first harness for installation to provide the first control application and f) supplying the industrial controller with the second instruction set and the second harness for installation to provide the second application. Advantageously, the method further comprises 1) defining first installer instructions and second installer instructions for each of the applications, 2) defining a first installer installing the controller with the first instruction set and the first harness in accordance with the first installer instructions and 3) a second installer installing the controller with the second instruction set and the second harness in accordance with said second installer instructions. Preferably, the method further comprises the step of installing the first industrial controller in a first standard electrical junction box. More preferably, the method comprises the step of installing the second industrial controller in a second standard electrical junction box. Advantageously, the method further comprises the step of directly connecting the first industrial controller to electrical mains having a first voltage. The method may further comprise the step of directly connecting the second industrial controller to electrical mains having a second voltage different from the first voltage.
It is an object of the present invention to obviate or mitigate the disadvantages of known methods and apparatus for controlling controlled devices using an industrial controller. It is a further object of the present invention to provide an industrial controller that combines many advantages over the prior art. Being of a generic design, it allows the manufacturer to optimize its production while minimizing the product cost. Moreover, it is easily configurable by using a standard programming language to define the drivers while still providing these latter for quick and easy programming of the controller by a typical user using an instruction set. By combining the power supply and by using standard connectors, the controller assembly fits nicely in a convenient economical standard electrical box. Furthermore, by using harnesses, installation time and cost is minimized. It is still a further object of the present invention to provide a method for providing a generic industrial controller that may be used in different applications to control different controlled devices by providing different instruction sets and different harnesses. It is still another object of the present invention to provide an assembly of industrial controllers being identical except for their instruction sets and for the length of their harnesses.
A detailed description of examples of implementation of the present invention is provided herein below in which reference is made to the following drawings, in which:
Turning now to
The processor 35 receives input signals 26 (not shown) from sensors, probes or other such devices through the input connector 40. The female part 40a of input connector 40 is fixed to the printed circuit board 32. Based on these input signals 26 and the instruction set 100 it caries, the processor 35 sends outputs signals 28 (not shown) to controlled devices 30, shown in
The industrial controller further uses communication ports for networking with other industrial controllers for example. Preferably, RS-485 ports are used for both the incoming communication port 80 and the outgoing communication port 82. For applications in commercial or industrial building, the BACnet™ and/or Modbus™ communication standards are preferably used. Such networking capabilities are well known in the art and will not be explained in further details. The industrial controller 10 also includes a service port 90. The service port is used to connect the industrial controller 10 to the computer 20, shown in
Typical installations of industrial controllers require a separate, power supply to convert the voltage coming from the electrical mains 15 (shown in
Advantageously, the industrial controller 10 is designed to occupy as little space as possible such that it may be inserted in a standard electrical junction box 65 of dimensions 4 11/16 inches×4 11/16 inches. The printed circuit board 32 is mounted directly in its housing 67, which may either be used as is, or preferably placed in an electrical junction box 65. The housing 67 is then fixed to the interior surface of the electrical box cover 68. The electrical box cover 68 is then fixed to the electrical junction box 65, as it would normally be, totally enclosing the industrial controller 10 within the electrical junction box 65. Alternatively, the industrial controller 10 could be mounted directly at the bottom of the electrical junction box 65. Using a standard electrical junction box provides many advantages. An electrical junction box is cheap, already designed to be mounted to the structure of a building and is also approved for electrical connections.
For its power supply input, the industrial controller 10 may be directly connected to an electricity source, such as an electric panel, or preferably, be connected to a standard electric outlet via a standard connector. Hence, a power cord having a standard electrical plug 75 at one end and a male portion 74b of a power supply connector 74 at the other end is preferably used. The male portion 74b of the power supply connector 74 matches a female portion 74a fixed on the printed circuit board 32. The standard electrical plug 75 connects to the electrical mains 15 shown in
Referring again to
For example, in a different embodiment of the present invention, a set of industrial controllers is used (only one controller is shown in
In an industrial application, the industrial controllers 10 may, in particular, be sold to a product manufacturer who integrates these industrial controllers 10 in the design of his products.
It will of course be appreciated that many modifications and alternative embodiments are possible within the broad scope of the present invention. For example, in some applications it may advantageous to invert the male and female parts of the connectors. As long as the connector part on the harness and the connector part on the printed circuit board match together, many variations may be done.
It may alternatively be envisioned to use an extension card on the industrial controller 10 for Ethernet communication, either wirelessly or through fiber optic. The industrial controller 10 could be in communication with a remote computer through a HTML (web based) server application. Furthermore, other input/outputs for specific applications could be installed piggy-back via a communication bus.
The invention is not limited in its application to the details of the arrangement of components illustrated in the accompanying drawings, or the description of the steps referred to above, but is defined by the claims that follow.
