I’m creating industrial automation projects based on Delta IA products. So far I am using serial connections or ethernet for my projects. For more than a year I am trying to understand the CANopen protocol. Delta has a lot of products that support CANopen. The problem I’m facing is the CANopen understanding. Its more easy to understand something by comparing to something we already know. In my case I’m well known of instructions, operands, addresses and other terms. So what are SDO, PDO, NMT? Are they instructions, operands or something else?! Where is this EDS file located? Do we download it from somewhere? If yes do we download it to the PLC or keep it on the notebook? Where is object dictionary located? Do we create it?
A lot of people think (quite rightly so) that the CANopen explanations are very unclear and do not use the right approach to the users who want to understand the matter.
Thank you!
I tried to learn all that stuff from datasheets regarding CANopen and thats exactly the problem…
There is a series of short videos on YouTube especially to help newcomers to CANopen like you. You can find it here.
For a general overview of all important communication objects in CANopen including EMCY, as well as some other core concepts, see this poster in PDF format here.
Once you understand more, you should request a copy of the CiA 301 standard where all the basics are specified here. Yes, it's very technical but an indispensable reference if you are unclear about certain details.