RE: control knobs to a new control system

[Andreas Luedeke <andreas.luedeke@psi.ch>]

Hi Mauro,
at PSI we use a "knob-box", where you can assign an EPICS PV to a 
physical wheel. Four of this wheels are in one box.
A touch screen above these wheels show the actual value of the PV and 
allows you to control the step size of the wheel, set the former 
set-point (old value), or to type a numeric value to a device.
Unfortunately the box is an in-house design, you cannot buy it 
off-the-shelf. Rob Emery's solution sounds more promising for you.
A knob-box is very nice if you want to fine tune a couple of devices 
simultaneously without looking at the screen or the keyboard.
But I agree with Emmanuel that you can achieve the same thing with 
keyboard control. MEDM or QtDM supports in addition to sliders the so 
calls "wheelswitch". In QtDM this can be controlled by the keyboard, as 
well as a slider can. It may needs a little bid of initial effort to 
create key-bindings that work for you, since switching from one device 
to the other is not yet supported. But it is maybe less effort then the 
long term support of the control knobs hardware.
Cheers
Andreas