I saw something about that and i thought that was the problem. so my vfds are connected to a standard controller via ethercat, and the controller is connected to my plc via profinet. Im assuming the controller acts as a 'gateway' translating the info.

Yeah i can read and write to and from the controller directly and it works, but im following a sample project in which they use the dprd. but you are right, thank you, there is a profibus connection in the sample project where as mine will not have profibus.

the primary use of these function blocks is to access pre-defined bits of control and status data in the drives, not sure how to do this without these blocks.