Its been a while since I played with one of these, but I will give it a shot.
1, No software - all MB+ addresses are selected with hardware switches, usually on the back of the unit. I actually find this to be one of the best ways to run a well planned and well documented system.
2, Concept, when you plug into a MB+ cable, you will get a list of MB+ addresses, with CPUs indicated. This does not tell you what the other units are, but does give you a list of addresses and will tell you if there is any HW comms faults.
3, Test package, I can't remember the name of this, but the Schneider reps around were I live used to give it away free. This was a DOS package that would interogate the MB+ bus and provide a list of addresses. It would also allow you to pass data directly and was good for testing and learning how a device worked.
4, PLC software?
Don't know, and never tried.
I would also ask, why you would want to do this?
Normally, you would specify the address and set the CPU to this address. I can't see how a MB+ network could even operate any other way.
Doug