The USB2AX is a small interface to control Dynamixel servos like the AX-12 from a computer. It plugs into a USB port and has a 3-pin Dynamixel connector to be connected to the servos.
A typical use scenario is in a small mobile robot with a laptop or an embedded computer (like a Raspberry PI) as a brain and servos to move legs, arms or claws.
What servos can it talk to?
Basically, it can talk with any device which uses a half-duplex TTL interface (3-pins connector) and the Dynamixel protocol. More specifically:
All of the AX servos (AX-12/AX-12+/AX-12A, AX-12W, AX-18F/AX-18A).
The "T" versions of the MX servos (MX-28T, MX-64T, MX-106T).
(Unsupported) It can probably communicate with some other servos that use the same protocol and interface as the AX servos, like the CDS5500.
What can't it do?
The USB2AX can not communicate with the Dynamixel servos using the RS485 interface (the one with 4 pins).
Neither can it control any sort of hobby/RC servos or other brand of robot servos.
Compared to the USB2Dynamixel, it also lacks the RS232 port (with its big DB9 connector) used to program some controllers from Robotis like the CM-510.
It can not supply power to the servos.
It is not a generic USB to Serial (even though it can be modified to be one) and has very different capabilities than the LN-101.
Comunication with AX and MX Dynamixel servos (with 3 wires) @ 1Mbps
Very small (16x36mm)
Protection against ESD and short circuits
Advanced functionalities: sync_read, bulk_read...
Windows / Linux / MacOS
Open Source Software & Hardware, programmable and hackable!
Driver (for Windows): usb2ax.inf
For documentation, CAD files, sources: xevelabs.com