CANopen Hands-On Tutorial - Mbed

[Pages:36]Embedded Systems Academy CANopen Hands-On Tutorial

CANopen Hands-On Tutorial

An Introduction to CANopen

using

CANopen Magic ProDS Eval

Presented by Olaf Pfeiffer EMBEDDED SYSTEMS ACADEMY

CANopenHOT July 2005

Slide 1



Prerequisites

All hands-on examples in this tutorial use the program ? CANopen Magic ProDS Eval

This tool allows simulation, configuration, analyzing and testing CANopen networks ? No hardware required ? All CANopen communication is simulated

Download and install from ?

CANopenHOT July 2005

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Embedded Systems Academy CANopen Hands-On Tutorial

Our CANopen Book:

Embedded Networking with CAN and CANopen

CANopenHOT July 2005

Slide 3

Published by Annabooks / RTCBooks

3 Parts

? Using CANopen Introductory level up to system integration

? CANopen Engineering Developing CANopen nodes

? CANopen Reference Quick access to all info required by integrators and developers



Contents

1. Physical Settings ? Physical layers ? Message basics

2. Network Nodes ? Unique node IDs ? Default connection set

3. Boot-up, Heartbeat Network Management (NMT) ? Boot-up message ? Heartbeat messages ? NMT state machine ? NMT Master message

CANopenHOT July 2005

Slide 4

4. Object Dictionary ? Organizing the data communicated ? Electronic Data Sheets ? Service Data Objects

5. Process Data Objects (PDO) Communication Parameters ? Message IDs and PDO Linking ? PDO Triggering

6. PDO Mapping Parameters ? PDO Contents

7. Device Configuration File ? Save and Restore Configuration

8. Advanced Features



Embedded Systems Academy CANopen Hands-On Tutorial

CANopen Hands-On Tutorial ? Part 1

Physical Settings

Network physical layer, message basics,

communication bit rates

CANopen is optimized for CAN

CANopen is `open' to be used on a variety of networking technologies ? CANopen on Ethernet - Ethernet- ? CANopen on UART, I2C, LIN -

However, it is optimized to be used on Controller Area Network (CAN) ? Using a maximum of 8 data bytes ? Using message identifiers 0-1023

CANopenHOT July 2005

Slide 6



Embedded Systems Academy CANopen Hands-On Tutorial

CANopen Suitable Physical Layers

High-end PC or Workstation

PC or Workstation

High-end controller, Embedded PC or PLC

16 to 32 bit

Ethernet

8bit

CANopenHOT July 2005

Slide 7

MicroMessaging

Plant Management

Plant Control

Process Control

CAN

Controller Coupler

Sensors Actuators

What's in a single message?

Identifier 11 bits

Data bits (0..8 Bytes)

Control and security 36 bits

CANopenHOT July 2005

Slide 8

In CAN, a single messages is kept short and only contains up to 8 data bytes

Benefits:

? There can be many messages per second (rule over thumb: up to 10,000 per second at 1 Mbit, worst case of 20,000 per second)

? No single message can occupy/block the network for a long time

? Best for small sensors and actuators (I/O modules, encoder, push buttons, temperature,...)

Concept: send less data ? more often



Embedded Systems Academy CANopen Hands-On Tutorial

CANopen Network Speeds

When used on CAN, the specified networking bit rates are

? 10 kbps

? 20 kbps

? 50 kbps

? 125 kbps ? 250 kbps ? 500 kbps

Each of these can be added to the hardware settings of CANopen Magic ProDS Eval

? 800 kbps

? 1000 kbps

CANopenHOT July 2005

Slide 9

NOTE: CANopen Magic ProDS Eval Does not simulate network speed, available bandwidth only depends on the performance of the PC on which the simulation runs

Hands-On: Getting started

Start CANopen Magic ProDS Eval

CANopenHOT July 2005

Slide 10

Select `None' for the hardware and pick any network

? Networks are simulated "virtually" within the program. There is no "live" network traffic



Embedded Systems Academy CANopen Hands-On Tutorial

CANopen Hands-On Tutorial ? Part 2

Network Nodes

Unique Node IDs, message IDs used by nodes

Default Connection Set

Layout with CAN physical layer

Main network trunk with termination resistors ? Drop lines only permissible if bit rate is 500kbps or below

Each node must have a unique node ID ? In the range of 1 to 127

Maximum length depends on network speed ? Example: about 250m with 250kbps

CANopenHOT July 2005

Slide 12

Terminator

Trunk Line

Node Node

Tap Tap

Tap

Node

Drop Line Node

Node

Node

Node

Node

Terminator Tap

Node Node Node

Node



Embedded Systems Academy CANopen Hands-On Tutorial

Hands-On: Network Configuration

From the main menu, select Options ? Configure Network

Or press the Network Configuration tool button

CANopenHOT July 2005

Slide 13

Hands-On: Add nodes to the simulation

In the Network Configuration window, click on the `Add Node" button

Add two digital I/O nodes to the system

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Slide 14

1. Node ID `1'

2. Name `Digital I/O'

3. EDS File `Peak Digital 1.eds' from EDS directory

4. Add `2' nodes

5. Choose the simulated product `PCAN MicroMod Digital 1'

6. Click the `OK' button



Embedded Systems Academy CANopen Hands-On Tutorial

Hands-On: Run network simulation

Open Trace window, to see simulated network traffic ? From the main menu, select View ? Trace

To run the simulation, go to the main window and select the simulation tab

Click on `Run' to run the simulation of individual nodes or on the green triangle to run all nodes

Run all nodes

CANopenHOT July 2005

Slide 15

Simulation tab

Hands-On: View first messages

Look at the Trace window Each node produced 2 messages

? Bootup (701h and 702h) ? Emergency Clear (81h and 82h)

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Slide 16



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