DESIGN, IMPLEMENTATION AND TESTING OF A COMMUNICATION PROTOCOL FOR AN ACCESS CONTROL SYSTEM

Abstract

The Access control systems are specialized process control systems used in industries, big corporate offices for applications like controlling the access of individuals to a building, elevator control, fire control, and intrusion detection among others [1]. The access control system consists of a centrally located host and a network of micro-controllers distributed over the area under control. The host has database for the complete system and monitors the alarms and status information of all the micro-controllers [2]. The micro-controller is a microprocessor based controller, having the firmware and configuration data to operate the devices like alarm, sensors and relay panels, readers for magnetic, bar-code, and proximity type badges. This dissertation is concerned with the protocol used for host to micro-controller and inter micro-controller communication. The dissertation work involved understanding of the existing protocol used in older version of the micro-controller called Micro/5, for the purpose of designing, implementing and testing of the protocol for a new micro-controller, Micro/6. As a result of this project work, a communication protocol has been designed, implemented and tested for inter-Micro/6 and Micro/6 - host communication. The protocol is used for asynchronous transfer of variable size packets. It facilitates reliable transport of messages. It supports three different media channels - serial line (based on RS-232), dial-up line(modern connection) and network (based on LAN/WAN). The protocol handles the media channel failures and switches to back-up media channel in event of failure in the working channel. The coulmunication protocol also provides for diagnostic information for system debugging and fault diagnosis [3]. The major challenge in this project has been in reverse engineering of the existing protocol, which does not have sufficient documentation for Micro/5 and in designing it for a completely new system (Micro/6) with a different hardware architecture and a new operating system, embedded Linux. The complete design, coding and testing of the protocol was carried out at GE- India Business Center at Hyderabad. Six Sigma standards were used throughout the development phases to track and meet the performance specifications [4].