Communication Protocol; Communication Overview; Instruction Packet; Status Packet - Robotis Dynamixel AX-12 User Manual

DYNAMIXEL

3-1. Communication Overview

Packet
Communication
Unique ID
Protocol
AX-12

3. Communication Protocol

The main controller communicates with the Dynamixel units by sending and receiving
data packets. There are two types of packets; the "Instruction Packet" (sent from the
main controller to the Dynamixel actuators) and the "Status Packet" (sent from the
Dynamixel actuators to the main controller.)
Main
Controller
For the system connection below, if the main controller sends an instruction packet with
the ID set to N, only the Dynamixel unit with this ID value will return its respective status
packet and perform the required instruction.
Instruction Packet(ID=N)
Main
Controller
If multiple Dynamixel units have the same ID value, multiple packets sent
simultaneously collide, resulting in communication problems. Thus, it is imperative that
no Dynamixel units share the same ID in a network node.
The Dynamixel actuators communicate through asynchronous serial communication
with 8 bit, 1 stop bit and no parity.

Instruction Packet

Status Packet

ID=0 ID=1
Status Packet(ID=N)
9
ID=N