micrologix to compact logix with encoder

Currently using Micrologix 1400 and have a allen bradley encoder connected to inputs 0 and 1 which is the high speed counter input. Then use a STI to detect how fast a master conveyor belt on another piece of equipment is running. Then in the program of the PLC, control the speed of 5 other motors that are feeding fabric on top of the master fabric and going through a heat/press chamber to laminate all of the pieces together. This is working great, but now looking at possibly doing some more machines and use a compact logix plc and some allen braley Powerflex 525 drives and control the speeds of the drives through ethernet communications based on the master speed.
Confused as to how to connect the encoder into a compact logix plc and then be able to know the speed that master conveyor belt is running. Could someone that has been through this maybe try to unconfuse a old man trying to figure this out.
Thanks

I would use an encoder on the 525 and send the info to the controller. compact logix and 525's have endless possibilities communicating together.