I havn't done this yet but you should be able to have up/down with two input pins, some vb running a timer and countdown or count up of the fro.
I have an analogue through modbus, which I think is the better way to do it, and save some input pins on the lpt port.
If there is enough demand for just a modbus feedrate device, I could manufacture it. It would cost much less than a complete modbus system.
Whacko for $