NI 9505, programmatically determine if motor is connected.

[bscout]

I am working on an application where anywhere from 1-4 motors may be connected based on how the user wants to use the system.  As part of the application, the system goes through an initialization step to find the home position of the actuators and reset the encoder.  I would like this to excecute without user input.  The question is, does anyone know of a slick way of querying some value from the motor drive (9505) and using that to determine whether a motor is connected?  I thought about using current sense to somehow accomlish this.  Any ideas?

Bscout

[VGA_CD-ROM]

Hi bscout,
You could probably use current sensing, or if you have quadrature encoder feedback wired up, you could command a short move on each axis and see if your number of counts changes. The problem with doing any kind of closed-loop "test and verify" move like this is that if you do have a motor connected, you might be undesirably driving it without knowing what state it's already in. But since you are making each motor find a home position before doing any other work with them, that doesn't sound like a problem.

Alternatively, you might even just have each one look for home like you are already planning to do, and if one doesn't find a home position after the standard seek process you could assume that motor/axis was not connected.