DynamixelShield 
DynamixelShield Library for Arduino
This library inherits and uses Dynamixel2Arduino library. Therefore, it must be installed.
The reason for the distinction between DynamixelShield and Dynamixel2Arduino is that Dynamixel2Arduino is intended to be used on non-Shield hardware. The DynamixelShield library is DynamixelShield's dedicated library created by Dynamixel2Arduino.
Please refer to e-Manual for more information