CROSS-REFERENCE TO RELATED APPLICATIONS
FIELD OF THE INVENTION
This application claims the benefits of U.S. Provisional Application Ser. No. 60/224,088, filed Aug. 9, 2000.
- BACKGROUND OF THE INVENTION
The present invention relates generally to control systems, and more particularly to industrial input/output (I/O) networks and devices.
Industrial control systems are generally used for controlling processes that involve input/output (I/O) devices such as relays, solenoids, motors, valves, switches, and other electrical and electromechanical devices. The processes that are controlled include machining, drilling, welding, spraying paint, mixing materials, assembling parts, handling materials, etc.
There are several different types of industrial control systems. Some conventional programming and control systems use ladder diagrams and relay ladder logic (RLL) to control the operation of the I/O devices associated with the processes. In practice, however, programmers tend to use a flowchart to initially define the operation of the I/O devices in the process. Then, the programmers manually translate the flowchart into the ladder diagrams. The programmers employ the flowcharts as a first step because the flowcharts emulate human thought processes whereas the ladder diagrams do not. Some later-developed industrial control systems allow the designer to create flowcharts on a computer using a graphical user interface. These systems automatically generate the control logic from the flowchart. One flowchart-based system is disclosed in “Continuous Flowchart, Improved Data Format and Debugging System For Programming and Operation of Machines”, U.S. Pat. No. 4,852,047, which is hereby incorporated by reference.
- SUMMARY OF THE INVENTION
A significant problem encountered with both flowchart-based and RLL-based programs is the entry of parameters and other values for each of the I/O devices that are connected to the industrial control system. A process may include only a few I/O devices or may include hundreds of I/O devices. Each I/O device may have over 100 attributes. For example, a motor starter may have current and voltage limit attributes. Prior approaches have used time-consuming ways to configures the networked devices, such as requiring the manual entry of the name, attributes and/or parameters for each I/O device.
A system for cloning input/output (I/O) devices that are connected to a network of an industrial control system includes a first network coupled to a second network. A first plurality of I/O devices are connected to the first network. A second plurality of I/O devices are connected to the second network. A master computer is coupled to one of the first and second networks. The master computer includes control software with an object oriented model for defining attributes or parameters of the I/O devices on the first network to allow cloning of the I/O devices on the second network.
In other features of the invention, the object oriented model includes a hierarchical class structure with inheritance. The hierarchical class structure includes a device class and a plurality of device types. The object oriented model includes at least one class level hierarchically below the device class.
In still other features of the invention, the I/O devices instantiated at a class level inherit the attributes or parameters of the class level. The control software includes a graphical user interface for interfacing the control software and cloning the I/O devices. The I/O devices include barcode readers, sensors, actuators, motor starters and other similar devices.
BRIEF DESCRIPTION OF THE DRAWINGS
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the deta