Does anyone know how to get a rotary axis to only operate in only the positive direction?  It would roll over 360 and still move positive no matter what angle is commanded?

Process all of the moves as Incremental with no - (negative) values.
Maybe one way ......

General Config, have Rotation  Rollover chosen and you will then only get movements in one direction if you only call positive commands. For example if at A0 and you command G1A10F200 it will rotate clockwise to that position. If you then command A8 then it will continue in the same direction right round and past the 360 degrees to get to 8. If you want it to rotate the opposite way then yuou would command A-8.

Hood