Introduction to EtherCAT PDO's

A discussion pertaining to the architecture of EtherCAT PDO's, as well as the differences between fixed vs. non-fixed and transmit vs. receive.

[@dex-davidg8732]

Very helpful!

[@ajohn502]

In the beginning of the video you said the offset for multi-axes was 40. Later on in the video, you said the offset was 800. which one is correct?

[@CopleyControlsOfficial]

Excellent question. The multi-axis offset for object indices is 0x800 for objects in the range of 0x2000-0x27FF (Copley Specific Objects) and 0x6000-0x67FF (DS-402 Objects). The multi-axis offset for the object indices of the PDO's is 0x40. For example, let's say that TxPDO1 contains object 0x6041 (Status Word). The object index for TxPDO1 for Axis A would be 0x1A00 and would contain 0x6041. The object index for TxPDO1 for Axis B would be 0x1A40 and would contain 0x6841. Please read our helpful CANopen Programmer's Manual for more information. Link to the manual: copleycontrols.com/wp-content/uploads/2018/02/CANopen-Programmers-Manual-5.pdf