test specification for PLCCS: A Power Line Carrier Communications System submitted to: Professor Joseph Picone ECE 4512: Senior Design I Department of Electrical and Computer Engineering Mississippi State University Mississippi State, Mississippi 39762 February 14, 2000 submitted by: W. Kwan, W. Parker, B. Roberts, J. Tatum Faculty Advisor: Dr. Nicholas Younan Department of Electrical and Computer Engineering Mississippi State University Box 9571 Mississippi State, Mississippi 39762 Tel: 662-338-5361 email: [email protected], [email protected], [email protected], [email protected]: Communications System 1 ECE 4512 03/20/00 EXECUTIVE SUMMARY Technology in today’s world is advancing at a very rapid rate. Once a rare commodity, computers can now be found in hundreds of millions of homes and businesses [1]. A growing trend involving computers is industrial control and home automation, a practice in which electrical devices are controlled with little or no human interaction [2]. Although this may sound like a noble concept, many of these control systems suffer from poor performance in terms of data communications capability [3]. They also require the user to configure them locally, which makes it difficult to check the status of the systems from afar. Also, many systems carry a steep price tag that many potential buyers find unappealing [4]. To remedy the first of these issues, a new data communications system will be developed. The system will consist of one or more host units and multiple target units. The host units will initiate all data communications processes to the target units, and a target unit may reply only to the host that hails it. Only one communications process may exist at any given time per host, preventing data communication collisions. Existing electrical wiring will serve as the communications medium, preventing the expense of installing additional wiring in the building. The access issue will be remedied by designing a software package for a personal computer. The software will allow the host device to connect to a PC, as well as the Internet using TCP/IP. The user will therefore be able to access the host device through a standard Internet connection. A third issue is the cost of comparable control systems. Presently-available systems that are used in industry cost thousands of dollars [4]. By programming a microcontroller to emulate traditional hardware, less electronic components will be required to build a working system. As a result, overall production costs will be substantially lower than comparable systems. The production cost of each host and target unit will not exceed $35 and $30, respectively. The expected market price of a host unit will be $149.95, and the expected market price for each target unit will be $39.95. We will approach this project by dividing it into several key components. A modem will be designed that will allow the host and target units to communicate over the power line. Microcontroller firmware will be created to control the functionality of both host and target units. Circuitry and firmware will be implemented to interface the host unit to a PC. Software will be written to allow user-control over host and target units. Our design will be superior to presently-available device control systems in that ours will reduce the number of control errors due to corrupted data transmissions, thereby enhancing the reliability of the system. It will also provide an easy-to-use interface that will allow users to render remote control over all host and target units and all of their associated peripherals. Considering the ongoing growth in popularity of home and industrial control systems, this project has an abundant future [5]. Potential design enhancements include improving the data transfer rate of the modems and enhancing the remote web interface.PLCCS: Communications System 2 ECE 4512 03/20/00 1. INTRODUCTION The purpose of this project is to design and implement a device control system that utilizes a building’s existing electrical wiring as a communications medium. This design will give consumers a more cost-efficient device control solution. The design approach will consist of system design, simulation, construction, and field testing. The significance of the system is that any computer connected to the network may control all host and target units. The design constraints for our proposed system are as follows: 1. Data Transfer Rate: The data transmission speed of the power line carrier will be a minimum of 300 bits-per-second and a desired 600 bits-per-second. 2. Error Rate: An average of 1.5 data packets or less will be required for a message to successfully be exchanged. 3. System Structure: The system will be able to support up to a total of 4.29 billion host and target units. 4. Browser Compatibility: The web interface will be compatible with Netscape 3.0 and Microsoft Internet Explorer 3.0. 5. Power Usage: The host unit will consume no more than 1.5 watts. The target unit will consume no more than 4 watts. 6. Memory Capabilities: Each host unit will be able to store command profiles for up to 500 target units. 7. Electromagnetic Emissions: The system will conform to FCC rules and regulations §15.107 and §15.109. 8. Physical Packaging: Each host unit will be packaged in a container no larger than 1.75” high, 4” wide, and 6” deep. Each target unit will be no more than 2” high, 4” wide, and 5” deep. 9. Cost: The production cost of each host unit will not exceed $35; the expected market price for the host unit is $149.95. The production cost of each target unit will not exceed $30; the expected market price for the target unit is $39.95. These tests will ensure that the final product will work properly and will meet all the of the design constraints.PLCCS: Communications System 3 ECE 4512 03/20/00 2. TEST SPECIFICATION Several tests will be performed to ensure the accuracy of the system. The preliminary tests will ensure that the system operates correctly within the predefined requirements. To perform these tests, several software programs will be utilized. After a prototype system has been built, tests will be performed on the physical system to ensure proper operation. The
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