If the drives use the simple six-step scheme, where they only drive 2 of the 3 output terminals at a time, and only use the Hall commutation signals, this can be done by wiring a permanent configuration on the Hall inputs. You would have 2 of the hall inputs set to one condition (either high or low) and the one other input to the opposite condition. This would force the drive to always drive the same 2 output terminals.
The data sheet may have instructions on how to do this.
If the drive in question is sinusoidal or uses encoder feedback, then this cannot(generally) be done.
Jon
