H. F. Othman, Y. R. Aji, F. T. Fakhreddin, A. R. Al-Ali
Computer Engineering Department
American University of Sharjah, UAE
This paper presents Controller Area Networks (CAN), their architecture, protocol, and standards. As a result, an overview of CAN applications, in both the industrial and non-industrial fields, is surveyed. We also propose the extension of CAN applications to home automation. The proposed system is a stand-alone single-chip embedded system equipped with 5 CAN ports to monitor and control home appliances locally. Home owners can also remotely access their homes via GPRS modem to control and monitor their home appliances.
Index Terms — Controller Area Networks (CAN), Home Automation, Home Appliances, Industrial Applications, Non-industrial Applications, GPRS Network.
Nowadays, major communication networks can be divided into four types, namely: IP Core Network/Internet, Wireless LAN, 3G/4G Cellular Network and Ad-hoc PAN . The common usage for these networks is to carry text, audio and video content. Recently, some of these networks have been utilized in industrial automation to monitor and control industrial plants [2-5]. Another type of networks is the Controller Area Network. CAN is intended as a communication network between the control units in vehicles. Nowadays, CAN applications are gaining ground and it is extending to industrial automation including marine and aircrafts electronics, factories, cars, trucks and many others . The backbone of the Controller Area Network is a fast serial bus that is designed to provide a reliable, efficient, and a very economical link between sensors and actuators. CAN uses a twisted-pair cable to communicate at speeds up to 1 Mbits/sec, with up to 40 devices. CAN was originally developed to simplify the wiring in automobiles. In the past, automobile manufacturers used to connect devices in vehicles using point-to-point wiring systems. As more electronics and controllers are deployed to monitor and control vehicles, wiring started to become more complex, bulky, heavy and expensive. Automotive industry starts to reduce massive wires complexity with dedicated CAN link that provides low-cost, robust network, and multi-master communication system. Figure 1 shows the efficiency and the wiring-reduction caused by implementing CAN among multiple devices.
Fig.1. Wiring-reduction, Cost reduction with CAN
This paper presents a comprehensive overview of controller area networks, their architecture, protocol, and standards. Also, this paper gives an overview of CAN applications, in both the industrial and non-industrial fields. Due to CAN reliability, efficiency and robustness, we also propose the extension of CAN applications to home automation.
II. CAN Architecture, Standards and Protocol
CAN was originally developed by Robert Bosch (Germany, 1986) when Mercedes requested a communication system between three electronic control units in vehicles. Point to point communication was not suitable anymore, and the need of using a multi-master communication system became imperative. Although this origin can be traced to automotive industry, industrial automation rapidly showed the need of using such a popular bus system [6-7]. A CAN port is a two-wire, half duplex, high-speed network system that can reach a throughput up to 1 Mbits/sec . Data, control commands and devices status can be transmitted and/or received in well-structured frames. Theoretically, CAN is capable of linking up to 2032 devices on a single network; due to hardware limitation, only 110 nodes can be linked-up to construct a single network. 
Similar to the traditional OSI model and IP model, CAN has a 4-layer protocol: physical layer, transfer layer, object layer, and application layer as shown in figure 2 .
Fig.2. Layered Architecture...