Quickstart Guide

Step 1: Prerequisites

Before powering on your TK actuator, confirm you have:

48 VDC power supply rated ≥ 10 A continuous (20 A recommended for TK-480)
USB-UART adapter (included in evaluation kit) or EtherCAT/CAN interface card
Ubuntu 22.04 LTS with ROS 2 Humble, or Ubuntu 24.04 with ROS 2 Jazzy
Python 3.10+ for the firmware flash utility

Note: The TK-120 and TK-240 ship with a USB-UART adapter for initial configuration. The TK-480 ships with an M12 EtherCAT connector and requires an EtherCAT master (IgH or SOEM) for initial setup.

Step 2: Unboxing and Inspection

Each TK actuator ships with:

Actuator unit with protective output flange cap installed
USB-UART adapter (TK-120 / TK-240) or M12 EtherCAT cable (TK-480)
12-pin power + signal harness (600 mm)
Quick-reference card with default node ID and baud rate
Download link for the firmware package (TKND_FW_v2.x.tar.gz)

Inspect the output flange for any shipping damage before powering on. The flex-spline is the most mechanically sensitive component — if the output flange has visible impact marks, contact [email protected] before proceeding.

Step 3: First Power-On

Connect the 12-pin harness: pins 1–4 are 48 VDC power, pins 5–8 are GND, pins 9–12 are signal (UART TX/RX/GND/5V).

Pin 1–4:  48 VDC (+) — fused at 15 A per line
Pin 5–8:  GND
Pin 9:    UART TX (actuator → host)
Pin 10:   UART RX (host → actuator)
Pin 11:   GND signal
Pin 12:   5V out (for external sensor, 500 mA max)

Apply 48 VDC. The status LED (visible through the encoder connector housing) blinks green at 1 Hz — this indicates the actuator is in Pre-Operational state. If the LED blinks red, see error codes.

Step 4: Install Firmware Package

Download the firmware package from the link on your quick-reference card and extract:

tar xzf TKND_FW_v2.x.tar.gz
cd TKND_FW_v2.x
pip install -r requirements.txt
python flash.py --port /dev/ttyUSB0 --model tk-120

The flash utility confirms the firmware version and writes the latest build if the installed version is older. After flashing, install the ROS 2 package:

cd ros2_ws/src
git clone https://github.com/tendonkindle/tknd_ros2.git
cd ..
colcon build --packages-select tknd_ros2
source install/setup.bash

Step 5: First Torque Command

Start the micro-ROS agent in one terminal:

ros2 run micro_ros_agent micro_ros_agent serial \
  --dev /dev/ttyUSB0 \
  -b 921600

In a second terminal, verify the joint state topic is publishing:

ros2 topic echo /tk_joint_0/joint_state

You should see position, velocity, and torque fields updating at 100 Hz. Now send a torque command to verify the control loop is closed:

ros2 topic pub --once /tk_joint_0/cmd_torque \
  std_msgs/Float64 \
  '{data: 1.0}'

The actuator will apply 1.0 Nm of torque. The joint will move if unloaded, or hold position against a load. To switch to position control mode:

ros2 topic pub --once /tk_joint_0/cmd_pos \
  std_msgs/Float64 \
  '{data: 0.0}'