ROBOTIS e-Manual v1.09.00
To control the Dynamixel actuators, the main controller needs to convert its UART signals to the half duplex type. The recommended circuit diagram for this is shown below.

The connector pin assignments are as the following. The two connectors on the Dynamixel are connected pin to pin, thus the AX-12 can be operated with only one connector attached.

The LED of AX-12 flickers once if the power
is supplied to AX-12 properly via wiring.