Hi,
The difference between Entity Binded Controller and Non Binded Controller is only Entity. Usually if you are calling the methods from binded controller it will add the entity name in url (like OrgUnits entity below example) and for non binded controller it's doesn't required.
Non Binded controller
/Commerce/GetDeviceConfiguration()
Bound controller to OrgUnits Entity
/Commerce/OrgUnits/GetOrgUnitConfiguration
For your issue, I am not sure what error you are getting while calling entity bind controller method but I will suggest to check url. If url is correct as above then provide some more information like controller method name, error message, etc. I hope that is not custom controller.
Regards,
Ram
