The download offers four tutorials that allow to quickly get an insight into the kind of analysis that the tool allows to perform. It also provides a reference manual that describes all the functionalities offered by RTaW-Sim. There is a reference manual of the underlying data model. And finally, it explains the basic functioning scheme of the simulation model underlying RTaW-Sim.

The goal of the documentation is to allow you to get quickly an idea about the kind of investigations RTaW-Sim allows to conduct on CAN based communication Systems. It shows how to obtain statistics about the response times of CAN frames (i.e., the time between a frame is ready to be sent and the time it is received by all stations) and it is dedicated to the exploration of the simulation results. It analyzes respectively the effects of clock-drifts and transmission errors on response time maxima of CAN frames.

The evaluation of frame response times is the most basic feature of a CAN simulator and probably the most useful because having a precise idea of the frame response times on a CAN bus is difficult without a tool, as soon as there are more than a few frames. It should be pointed out that if the microcontroller clocks that drives the transmission are assumed to not drift apart, provided periodic transmissions, then the response times statistics converges very soon (basically two lcm of the frames periods is enough) and it is not needed to simulate for a longer duration. Of course, as soon the microcontroller clocks may have drifts, as it occurs in practice, then it is less obvious to know how long is enough but RTaW-Sim helps you in that regard with the possibility to visualy check the convergence of statistics.

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Recommended Literature

This document describes the bit timing settings using the Philips SJA1000 CAN controller.

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A Comprehensible Guide to J1939

The Controller Area Network (CAN) is a serial bus communications protocol developed by Bosch in the early 1980s. It defines a standard for efficient and reliable communication between sensor, actuator, controller, and other nodes in real-time applications. CAN is the de facto standard in a large variety of networked embedded control systems. The early CAN development was mainly supported by the vehicle industry: CAN is found in a variety of passenger cars, trucks, boats, spacecraft, and other types of vehicles. The protocol is also widely used today in industrial automation and other areas of networked embedded control, with applications in diverse products such as production machinery, medical equipment, building automation, weaving machines, and wheelchairs.

In the automotive industry, embedded control has grown from stand-alone systems to highly integrated and networked control systems. By networking electro-mechanical subsystems, it becomes possible to modularizefunctionalities and hardware, which facilitates reuse and adds capabilities. Fig. 1 shows an example of an electronic control unit (ECU) mounted on a diesel engine of a Scania truck. The ECU handles the control of engine, turbo, fan, etc. but also the CAN communication. Combining networks and mechatronic modules makes it possible to reduce both the cabling and the number of connectors, which facilitates production and increases reliability. Introducing networks in vehicles also makes it possible to more efficiently carry out diagnostics and to coordinate the operation of the separate subsystems.

For more information log on to:
http://www.md.kth.se/RTC/Papers/VehicleApplicationsCan2005.pdf

A Comprehensible Guide to Controller Area Network

Many network protocols are described using the seven layer Open System Interconnection (OSI) model. The Controller Area Network (CAN) protocol defines the Data Link Layer and part of the Physical Layer in the OSI model. The remaining physical layer (and all of the higher layers) are not defined by the CAN specification. These other layers can either be defined by the system designer, or they can be implemented using existing non-proprietary Higher Layer Protocols (HLPs) and physical layers.

The Data Link Layer is defined by the CAN specification. The Logical Link Control (LLC) manages the overload control and notification, message filtering and recovery management functions.  The Medium Access Control (MAC) performs the data encapsulation/decapsulation, error detection and control, bit stuffing/destuffing and the serialization and deserialization functions.

The Physical Medium Attachment (PMA) and Medium Dependent Interface (MDI) are the two parts of the physical layer which are not defined by CAN.  The Physical Signaling (PS) portion of the physical layer is defined by the CAN specification.  The system designer can choose any driver/receiver and transport medium as long as the PS requirements are met.

The International Standards Organization (ISO) has defined a standard which incorporates the CAN specification as well as the physical layer. The standard, ISO-11898, was originally created for high-speed in-vehicle communications using CAN. ISO-11898 specifies the physical layer to ensure compatibility between CAN transceivers.

A CAN controller typically implements the entire CAN specification in hardware. The PMA is not defined by CAN, however, it is defined by ISO-11898. This document discusses the MCP2551 CAN transceiver and how it fits in with the ISO-11898 specification.

For more information log on to:
http://ww1.microchip.com/downloads/en/AppNotes/00228a.pdf

A Comprehensible Guide to Controller Area Network

The CAN-EngineTM (CANE) is a high performance, low cost, C/C++ programmable embedded controller with CAN support. It is intended for networking, automotive, industrial process control, high-speed data acquisition, and especially ideal for OEM applications.

A Controller Area Network (CAN) controller (SJA1000, 20 MHz clock) can be installed along with on-board CAN transceiver. Supported baud rates range from 300 bps to 1 Mbps, and interrupt-driven buffering software allows reliable, efficient delivery and receipt of packets over the CAN network. CAN control egisters on the SJA1000 are accessible in software.

A Fast Ethernet Module can also be installed to provide 100M BaseT network connectivity. This Ethernet module has a hardware LSI TCP/IP stack. It implements TCP/IP, UDP, ICMP and ARP in hardware, supporting internet protocol DLC and MAC. The hardware Ethernet module releases internet connectivity and protocol processing from the host processor, which represents a huge improvement over software-based TCP/IP stacks. The resulting system can easily handle transmissions in the 100KB/s+ range in real world applications. It supports 4 independent stack connections simultaneously at a 4Mbps protocol processing speed. Software libraries and demo project are available for Ethernet connectivity.

A 16-bit parallel ADC (AD7655, 0-5V) supports ultra high-speed (1 MHz conversion rate) analog signal acquisition. The AD7655 contains two low noise, high bandwidth track-and-hold amplifiers that allow simultaneous sampling on two channels. Each track-and hold amplifier has a multiplexer in front to provide a total of 4 channels analog inputs. The 16-bit parallel ADC requires only two CPU I/O operations (one start, one read) to complete a 16-bit ADC reading. With on-board precision 2.5V reference, the ADC accepts 0-5V analog inputs at 16-bit resolution of 0-65,535.

The CANE supports up to 2 GB mass storage CompactFlash cards with Windows compatible FAT filesystem support, allowing user easily transfer large amounts of data to or from a PC.

The CANE features fast execution times through 16-bit ACTF Flash (256 KW) and battery-backed SRAM (256 KW). It also includes 3 timers, PWMs, 20+ PIOs, 512-byte serial EEPROM, two RS232 ports, 3 timer/counters, and a watchdog timer. The three 16-bit timers can be used to count or time external events, up to 10 MHz, or to generate non-repetitive or variable-duty-cycle waveforms as PWM outputs. The PIO pins are multifunctional and user programmable. A real time clock (DS1337, Dallas) is available.

The CANE can be powered by regulated 5V DC or unregulated 9-12V DC with installing a 5V regulator. The CANE works with TERN expansion boards including the P52, P100 and MotionC.

For more information log on to:
http://www.tern.com/portal/content.asp?contentid=909&gclid=CNKX8OGVj5sCFeFL5QodFFEnpw

A Comprehensible Guide to Controller Area Network

The Controller Area Network (CAN) is a serial communication protocol designed for providing reliable high−speed data transmission in harsh environments. CAN system designers are being challenged to meet stringentElectromagnetic Interference (EMI) and Electrostatic Discharge (ESD) standards and increase reliability, whilereducing the size and cost of their products. This document provides guidelines to select a CAN bus protection circuitthat can prevent conducted and radiated EMI and ESD noise problems. The attributes of several practical CAN busprotection circuits will be analyzed using discrete filters, common mode chokes and Transient Voltage Suppression(TVS) devices.

Bus protection circuits are used to supplement the noise immunity level of CAN transceivers. Many of the secondgeneration CAN transceivers meet the minimum transient overvoltage test levels; however, higher immunity levels can be easily achieved by adding external EMI/ESD protection circuits. The CAN bus protection circuits improve the reliability of the CAN module, without significantly adding to the cost and complexity of the transceiver circuit.

Control systems can be implemented using either a centralized or a distributed architecture. A centralized control system typically consists of a single, relatively complex control unit that is used to perform multiple tasks and monitor several sensors. In contrast, a distributed control system consists of many controllers that perform a specialized task. The sensors, actuators and motors in a centralized system require point to point wiring in order to exchange information with the control unit, while a distributed system requires only a few wires to connect all of the control units. Also, each control unit in a distributed system, such as the CAN bus can be implemented with a low cost microprocessor.

For more information log on to:
http://www.onsemi.com/pub_link/Collateral/NUP2105L-APP.PDF