SDORead RET value 390E "Communication Channel is Busy" for all SLOT numbers, ERR light double flashing

Whenever I try to initiate a SDORead command, the RET value always returns 390Eh, meaning “Communication Channel is Busy”. I have this same problem no matter what I set the SLOT input value to.

Accordingly, the ERR light on the CM module is double-flashing; the results from Get Node and Network Status show that the “Network is not Ready” and there is a “Node error control event”, the the “Configuration Error” bit for my slave device is set. My slave device is a Nanotec PD4 stepper motor with CANopen controller.

Does anyone have any idea what may be causing this?

Have you followed this manual to set up the project:

Do you have the correct EDS file for Nanotec stepper motor?

If so, can you share your TIA project and its Configuration Studio project.
(need *.copprj and the complete folder .XPR (: name of the project) of the Configuration Studio project)

I am using the correct EDS file from the manufacturer. And I followed the manual for my configuration.

After hours of playing with settings, I found that the reason I was having problems is because I had the “CANopen Manager auto configuration” checkbox set in TIA Portal under the module’s hardware configuration. Unchecking this box solved the problem for me.