Using Real-Time Data Exchange

Tyler_Berryman 2017-01-17

Hey guys,

I was wondering if anyone has used the RTDE offered by Universal Robots? I think I remember hearing that you can log data from the robot directly to a USB stick using the real-time data exchange? Is anyone using this tool to log data?

matthewd92 2017-01-17

We use it to monitor the robot in the cloud by pulling back the state. We also do some control of the robot using it. The game that we built last year was fully driven off of this data layer.

Its not not as simple as just plugging in a USB stick though. They have a python library that you can use to create a data logger. There's an example of this on the support site that may do what you want.

If if you have any questions let me know. Im definitely not an expert on python but understand the basics of how the library works. We wrote our own that we use in node.js.

AndyC 2018-10-17

Can you describe the type of control you did, was it just the joints (or cartesian positions) or could you also control the tool? I am controlling a UR5 with a Robotiq Hand-e gripper and looking to consolidate to just one communications channel (or maybe 2 since I will always need the Dashboard). I want to do the obvious stuff (command by joints or cartesian values) but also need to control the 2-finger gripper and I prefer to use the RTDE if I can since it is fast and bidirectional. I prefer not to have to run custom programs or scripts on the controller but so far I have not found a way to achieve tool control without doing that. Thanks!

matthewd92 2018-10-29

We didn't use a gripper in the demo that we did, we used a vacuum tool that was actuated with a digital output so we just sent commands to the server to turn it on and off. I know with the 2F-85 we were able to write a driver that used the modbus communications to control the gripper, we just plugged it directly into the PC and not into the robot for that demo. It would be another server on the PC that you would need to write but then you could just send commands to that server from your PC control program. I have not worked with Hand-E at all so not sure if it is using a similar communications protocol. I know some of the other electric grippers on the market that plug into the tool port just use digital outputs so maybe Hand-E is doing the same thing but I don't believe so.

lakshmip001 2018-11-28

I want to use RTDE between PC and UR Robot to get status when robot is protective stopped or inverse kinematics not found error. Is it possible to do? If possible what would be program using python?

Thanks,

Lakshmi.

AndyC 2018-12-07

matthewd92: Thanks for that response. In the end I wrote a script that watched the RTDE input registers in a custom input recipe and then performed an action based on the codes we sent. The script then called the gripper commands that are available in the associated URCap. Wish I didn't have to write all that code (on two machines) just to move/pick/place but could not see any other way. But the up-side is I can access all the URScript math functions so that is nice to have. I still support the Dashboard interface as well so that I can launch my script when it isn't running.

lakshmip001: Yes it is possible, and the existing python example UR provides can be adapted easily to your needs (I did my interface in C# and I can't share the code).

AndyC 2018-12-07

matthewd92: Thanks for that response. In the end I wrote a script that watched the RTDE input registers in a custom input recipe and then performed an action based on the codes we sent. The script then called the gripper commands that are available in the associated URCap. Wish I didn't have to write all that code (on two machines) just to move/pick/place but could not see any other way. But the up-side is I can access all the URScript math functions so that is nice to have. I still support the Dashboard interface as well so that I can launch my script when it isn't running.

lakshmip001: Yes it is possible, and the existing python example UR provides can be adapted easily to your needs (I did my interface in C# and I can't share the code).

lakshmip001 2018-12-12

@AndyC I am able to detect protective stop and unlock protective stop using dashboard commands. But I still have problem with error: getinverse(): unable to find solution. Kindly please guide me through reference or how I can achieve it using RTDE of Universal Robot.