Physical structure of a CANopen network

Two basic conditions must be fulfilled in order that a CANopen network can function from a physical point of view:

• All nodes must be configured to the same bit rate and
• No node-ID may exist twice.

Unfortunately there are no mechanisms with which these conditions can be automatically ensured, so that the system integrator must check the bit rate and node-ID of every single network node when wiring a network and adjust if necessary. Normally the node-ID is configured directly on the device via DIP-switches or hexadecimal rotary switches. Alternative solutions require setting of these parameters via two reserved CAN identifiers by software with the aid of the so-called "LSS-service" (layer setting service). Here the device to be configured is to be connected 1:1 with a configuration device.
 
As generally required for CAN networks, both ends of the network must be terminated with a 120-Ohm terminal resistance between wire 2 (CAN_L) and wire 7 (CAN_H). In addition, the maximum permissible branch lengths for connection of the individual network nodes are to be observed.
 
The recommended permissible bit rates for a CANopen-network are given in DS-301: 10 kbps, 20 kbps, 50 kbps, 125 kbps, 250 kbps, 500 kbps, 800 kbps and 1000 kbps. In DS-301 a recommendation for the configuration of the bit timing is also given.

With our partner IXXAT Automotion Gmbh we offer the following products supporting engineers developing with CANopen:

Protocol Software

• CANopen Protocol Software >>>
  The CANopen Protocol Software includes all the necessary functions to implement slave or simple master devices according to the CANopen specification CiA 301. Support for LSS services according to CiA 305 is included as standard.

• CANopen Manager Software >>>
  The CANopen Manager Software is a very powerful software package that is optimally tailored at the implementation of complex CANopen manager devices. In particular, the software package is suited for the implementation of CANopen PLC devices and is based on the specifications CiA 301, CiA 302 and CiA 405.

• CANopenRT (Real-Time) Software >>>
  The CANopenRT Software is an optimised version of the CANopen Protocol Software featuring enhanced interfaces which permit a highly efficient integration with either real-time or mainstream operating systems. The software is particularly well-suited for multi-threaded applications requiring CANopen connectivity.

• CANopen Maritime Software >>>
  The CANopen Maritime Software implements the CANopen framework for maritime electronics, CiA 307, and is specially designed for the increased safety standards required by maritime automation. It offers a single-point-of-failure tolerance due to redundant communication and support of the flying master concept.

• CANopen Master API >>>
  The CANopen Master API is a software package that allows easy development of CANopen master applications such as control, service and test programs under Windows. The CANopen Master API is particularly well suited for applications that do not require flexible configuration over the CANopen network.

• CANopen Manager API >>>
  The CANopen Manager API is a powerful and flexible software solution that - in combination with a iPC-I XC16/PCI CAN interface - allows the user to implement generic CANopen control applications. It can also be integrated with IEC 61131-3 run-time environments on Microsoft Windows based platforms. It is based on the CANopen Manager Software, and thus fully supports the standardised CANopen boot-up procedure. The CANopen Manager API conforms to the specifications CiA 301, CiA 302, and CiA 405.

Tools

• CANopen Configuration Studio >>>
  The CANopen Configuration Studio is a convenient, powerful tool for the design and configuration of CANopen devices and networks. Highlights of the tool are its modularity and extendibility, and its concise representation of process data and network topology.

• CANopen EDS Editor >>>
  The CANopen EDS Editor enables convenient processing of EDS files. Its simple user interface offers device manufacturers and system integrators all the functions required to create or maintain existing EDS files.

• CANopen Device Manager >>>
  The CANopen Device Manager is a small, but extremely versatile tool targeted at all tasks requiring direct CANopen device access. These include device development and test, service and diagnostics tasks, as well as device configuration. CANopen Device Manager fully supports SDO, PDO and LSS master services as well as the download of configuration data and firmware update according to CiA 302. CANopen Device Manager particularly stands out with its flexible plug-in interface allowing the user to extend the basic functionality with optional add-on modules including a powerful scripting engine.

• canAnalyser with CANopen Module >>>
  The CANopen module option for canAnalyser interprets all received CAN messages in accordance with the CANopen specifications DS-301, DS-305, DS-401, DS-402, DS-405 and DS-406. The messages are recognised as SDOs, PDOs (also multiplexed), NMT, Emergency, Sync and Timestamp objects and interpreted accordingly. In addition, the Error Control, LSS and Flying Master protocols are interpreted. These are displayed in plaintext, colour-coded according to the message type. Interpretation of the data received is based on a configuration set. This either assigns an EDS/DCF file to each of the 127 possible network nodes or defines its device profile. The configuration set can be loaded, edited and saved. The profiles used for interpretation are integrated via external text files, whereby the CANopen module can be very easily extended by new profiles. Due to its flexible structure, the CANopen module can thus be used universally in all CANopen systems.