The functions of Primary(30001) Interface and Realtime(30003) Interface are almost the same.
Why UR create two Interface with the same functionality?
Would it be possible that the Primary has less a buffer for transmitting Message and data, so it get a lower update rate.
while realtime has a large buffer size so it get a faster update rate.
Primary inteface is used primarily to communicate between controller backend and GUI, and runs at 10Hz rate.
Realtime interface is used by fieldbuses, and URCaps, and runs at full control loop frequency 500Hz for eSeries, and 125Hz for CB3.
Both are documented as public interfaces, so for backwards compatibility reasons they will stay.