Robotis RX-28 - Manual (Page 8)

DYNAMIXEL RX-28
Connection to UART To control the Dynamixel actuators, the main controller needs to convert its UART
signals to the RS485 type. The recommended circuit diagram for this is shown below.\
CCW
VDD
VDD
The power is supplied to the Dynamixel actuator from the main controller through Pin 1
and Pin 2 of the Molex3P connector. (The circuit shown above is presented only to
explain the use of RS485 UART. The CM-2 PLUS controller already has the above
circuitry built in, thus the Dynamixel actuators can be directly connected to it)
The direction of data signals on the TTL level TxD and RxD depends on the
DIRECTION485 level as the following.
• When the DIRECTION485 level is High: the signal TxD is output as D+, D-
• When the DIRECTION485 level is Low: the signal D+, D- is input as RxD
RS485 UART A multi-drop method of connecting multiple Dynamixel actuators to a single node is
possible by using the RS485 UART. Thus a protocol that does not allow multiple
transmissions at the same time should be maintained when controlling the Dynamixel
actuators.
Main
Controller
7
[Multi Drop Link]