The ASDA-A2-M series of servo drives, is more advanced than the B2. For most CNC applications all these extra functions are not required. The A2 is very interesting for many other applications. It can be set into what's called PR mode, internal position mode. In internal position mode it's possible to attach for example a home switch, and you can then set parameters that will allow the drive + motor to home itself. Further you can set software limits of the range. Then you start a motion cycle by an event trigger switch. It is not like a PLC, it's much more simple. But for many applications this can be very interesting. Since all the intelligence is onboard, you don't need an extra PC or PLC or hours of programming.