Unable to Establish Communication Between Robotiq 3-Finger Adaptive Gripper and UR10 (CB3, PolyScope 3.15)

I am working with a UR10 CB-series robot running PolyScope 3.15, and a Robotiq 3-Finger Adaptive Gripper (3F) mounted on the robot wrist. The mechanical mounting is completed, and the gripper is powered correctly the Power LED on the gripper remains solid ON.

However, I am unable to establish communication between the gripper and the PolyScope teach pendant. The Communication LED blinks briefly at startup and then turns OFF, and it never turns back on.

I have already:

  • Installed the Robotiq 3-Finger Adaptive Gripper URCap compatible with CB-series robots

  • Verified that the URCap appears in PolyScope under URCaps

  • Navigated to Installation → Robotiq → 3-Finger Adaptive Gripper

Inside the URCap interface, I see options such as External Control and 3-Finger Adaptive Gripper, along with + / − buttons, license information, and configuration screens. However:

  • There is no explicit “Activate Gripper” button

  • After pressing the + icon, I am unsure which gripper/tool configuration to select and how to proceed

  • The communication LED on the gripper still does not turn on

My questions are:

  1. Is installing the URCap alone sufficient, or are there additional mandatory steps after installation?

  2. What is the correct procedure after pressing the + icon in the Robotiq URCap?

  3. Should the Communication LED remain ON or blinking once communication is established?

  4. Could this be caused by RS-485 wiring issues (A/B/GND), URCap version mismatch, or Tool Communication not being properly initialized?

  5. Are there any CB3-specific limitations or required power-cycle steps that could prevent communication?

Any guidance on the exact step-by-step procedure to properly activate and communicate with the Robotiq 3F gripper on UR10 CB3 (PolyScope 3.15) would be greatly appreciated.

Have you followed this guide from section 3.6? 3-Finger Gripper Instruction Manual

I have not tried the 3-Finger gripper before. It seems it uses MODBUS to communicate with the UR, and you never mention setting this up in your post.