Universal Robots Forum

URSim issues: Robotiq Grippers Installed but not Working

I’m trying to do more initial programming in the office instead of on the floor. I installed URSim a while back and am trying to get it to run my programs from the floor.

Robotiq Grippre URCaps version is installed and active in URSim.
PolyScope version is installed and running in URsim.

The grippers don’t show up on the Installation/URCaps/Grippers dashboard and they don’t register in the program. When the program gets to those nodes it says Gripper 1 (or 2) must be connected, blah blah blah. I have to suppress those nodes so I can get through the program.

How can I get the grippers to be detected?



I’m trying to do more programming from the office as well and have come up with 2 solutions that make it easier.

  1. To get the grippers to work in URSIM I use the latest URSIM in virtual box, my grippers are connected via a USB - RS485 convertor.
    Assuming you have usb access setup properly on the sim (open terminal and type lsusb, you should see the FTDI adapter in the list) and the URCap installed, You just need to manually start the driver.
    Mine happens to be located /home/ur/ursim-current/GUI/felix-cache/bundle191/data/com/robotiq/urcap/gripper/impl/daemon/robotiq_2f_gripper_driver.sh

Just search for it and run the robotiq_2f_gripper_driver.sh script as root.

  1. If I’m programming at the pendent or in the sim I’ll add the variable sim_mode and initialize it to false, then add an operator assignment for sim_mode. Then I move all my gripper actions(and any I/O that the sim doesn’t have) into IF statements checking the sim_mode variable. If SIm_mode = true, they are ignored, otherwise they run as they should.
    When I move to production I simply suppress the operator assignment and sim_mode remains FALSE.
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I’ve held off asking this because it sounds so stupid and I would be embarrassed for asking, but this is not the first time I’ve heard someone reference having physical grippers plugged in to their URSim.

To be clear, I am talking about the URSim that runs on my PC separate from my physical robots.

I have the robots out on the floor tending CNCs. I run them using the teach pendant.

I want to be able to simulate them in my office. Virtually. But my programs won’t run because it can’t find gripper 1 and gripper 2. The Robotiq URCap is installed in the simulator but they don’t show up in the Gripper tab and the programs don’t recognize them.

Am I mis-stating what URSim is or how I’m using it?

I’m sorry, I thought you were trying to get the physical grippers working with the URSim.

I had the same initial problem but also had a spare set of grippers to connect. As far as I know, you need the grippers connected to run with the Robotiq URCap. You may be able to run some sort of serial server to trick the simulator into thinking a gripper is attached.

I have heard that you can use a modified/alternative URcap with the simulator but have not found it yet personally.

I’ve also moved to adding the sim_mode flag I mentioned in my first post to all my programs I edit at my desk so I’m not sure I’ll invest much more into getting the URcap to work without a gripper installed. I’ll be sure to update if I do.

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Ahhh, thank you for clearing that up. I like the solution you use (variable and if statements to use the grippers). I may try to do something like that.

Of course, I’d much rather UR fix the URSim so it will run the Robotiq URCap in the sim-only, but at least I know where to go next.

Installing the URCaps in URSim will at least the change nodes from yellow to white. The nodes themselves are written by Robotiq, so perhaps you can reach out to them to see if they have a virtual version that will work without the hardware? My guess is they do some sort of check to see if they’re getting a signal from the gripper and throwing an error if they don’t get the right response.

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The URCap is already installed in the URSim so the nodes are already white. It’s when it reads the gripper nodes that it throws the “Gripper not connected” error, so yes, it’s not getting the feedback.

I will contact Robotiq about it. Thanks for the feedback.