EDS and Object Dictionary

Question

What are the EDS and OD? How are they created and used?

How it is that the OD comes in between the application and the CAN interface?

Answer 1

At first you should read a little bit about CANopen to get familiar with the concepts. Check www.canopen.de where you can download some specifications for free.

EDS is an abbreviation for Electronic Data Sheet. This is a text file in a specified format that contains all information about a CANopen device (a list of all supported ojects). You can edit it with a plain text editor or some commercial tools.

A CANopen-Master, that reads the EDS of a CANopen device, is able to access to the object dictionary of the device. The OD is an internal representation of all the data and functions that the CANopen device provides on the CAN bus.

The creation and usage of the obect dictionary depends on the CANopen stack you are using. It is somwhere between the CANopen stack and your application.