Robotiq 2F-85 Functionality Test Tutorial

This tutorial tests a Robotiq 2F-85 (or compatible Robotiq two-finger gripper) before it is integrated with a robot or an RL system. It covers an isolated Python environment, USB-to-RS485 setup, expected command output, safe motion tests, SERL integration, and common failures.

The test program is robotiq_2f85_function_test.py. It supports:

1. Direct Modbus RTU — recommended for the first bench test. The computer communicates with the gripper through a USB-to-RS485 adapter; ROS, SERL, and a Franka arm are not required.
2. SERL HTTP — use after the gripper works through SERL’s running franka_server.py.

If the gripper label says WF-85 rather than 2F-85, verify the exact model and electrical interface before sending motion commands.

0. Safety and prerequisites

Before applying power or sending a motion command:

• Keep hands, tools, clothing, and cables out of the finger path.
• Secure the gripper and adapter wiring so finger motion cannot pull on them.
• Use a current-capable 24 V DC supply appropriate for the gripper. Do not power the gripper from the USB adapter.
• Start with low force, such as -force 30 to -force 50.
• Use a soft, expendable object for contact tests.
• If the gripper is mounted on a Franka arm, disable or safely immobilize the arm for gripper-only testing.
• Ensure that only one process controls the serial port or gripper server.

Commands in this guide assume the terminal is in this repository:

cd /data/code/grippers/robotiq_tutorial
pwd
ls robotiq_2f85_function_test.py

Expected result:

/data/code/grippers/robotiq_tutorial
robotiq_2f85_function_test.py