jogging non-axis stepgen

I have two steppers running in velocity mode from a "hypot" input that would be handy to be able to jog with a pair of push buttons on the machine. They are on stepgen.6 and stepgen.7 but could be moved if necassary. I understand wiring switches to the BOB but am a little clueless as what to do next. One thought was to set up to more stepgens with a fixed velocity and piggy back them to the same pins on the BOB that would only be active when there is no other motion but I was hoping for a better, safer method.

The machine is for making custom rugs/carpets and the steppers control the needle movement and the yarn feed syncronized to the X/Y movement, which works well, and the jogging would assist with threading.

Thanks, Badger

one possibility is this:

wire the stepgen velocity command to the output of a limit2 component (to limit acceleration)
the input to the limit2 component is an output of a mux2 component
input0 of the mux2 component is your normal hypot output
input1 of the mux2 component is set to the jog velocity
the select input of the mux component is the jog command

EDIT:
(you probably want to interlock the jog command with some gating so it cannot be asserted when running)

PCW-

Thanks, I think mux2 will do what I need. As a causal user who has tried to read and understand all of the documentation, with moderate success, the forums and their contributors are a lifesaver. I will post the Rugbot once it's up and running.