UR5 reverse interface keeps dropping in WSL2

[AGuthmann]

Affected ROS2 Driver version(s)

2.4.3-1jammy.20240228.072527

Used ROS distribution.

Rolling

Which combination of platform is the ROS driver running on.

Windows using WSL2

How is the UR ROS2 Driver installed.

From binary packets

Which robot platform is the driver connected to.

UR CB3 robot, Real robot

Robot SW / URSim version(s)

3.15.8

How is the ROS driver used.

Through the robot teach pendant using External Control URCap

Issue details

Summary

I'm currently trying to setup the driver with a real UR5 Robot and after launching the external control program on the Teach Panel the reverse interface keeps loosing connection and reconnecting.

Issue details

Platform used: WSL2 (Ubuntu 22.04.4) on Windows 10 (22H2)
Laptop and Robot are directly connected via ethernet cable, can ping Robot from Windows as well as from WSL2.
I'm launching the driver with custom urdf-file and ur_type:=ur5 robot_ip:=192.168.1.10 launch_rviz:=false reverse_ip:=192.168.1.254 .
The Driver starts fine until here, when i start the external control program on the TP the driver shows robot requested program , , sent program to robot and Robot connected to reverse interface. Ready to receive control commands. immediately followed by Connection to reverse interface dropped., which pops up every second.

I found this Issue for the first version of the driver and the follow up for the ros2 driver #534, and tried to add keep_alive_count to the driver call, but the connection keeps dropping.

Steps to Reproduce

1. Install ros-rolling-desktop, ros-rolling-ur and dependencies
2. Install URCap (external-control-1.0.5) on UR5 and create program for external control
3. Connect laptop with robot
4. Start driver
5. Start external-control program

Expected Behavior

Robot connects to reverse interface and waits for movement commands.

Actual Behavior

Robot connects to reverse interface and immediately looses connection, then reconnects only to loose connection again and so on.

Relevant log output

[ur_ros2_control_node-1] [INFO] [1709625804.751190441] [UR_Client_Library:]: Robot requested program
[ur_ros2_control_node-1] [INFO] [1709625804.751516175] [UR_Client_Library:]: Sent program to robot
[ur_ros2_control_node-1] [INFO] [1709625804.950769462] [UR_Client_Library:]: Robot connected to reverse interface. Ready to receive control commands.
[ur_ros2_control_node-1] [INFO] [1709625807.084426649] [UR_Client_Library:]: Connection to reverse interface dropped.
[ur_ros2_control_node-1] [INFO] [1709625807.087728689] [UR_Client_Library:]: Robot connected to reverse interface. Ready to receive control commands.
[ur_ros2_control_node-1] [INFO] [1709625809.212327378] [UR_Client_Library:]: Connection to reverse interface dropped.
[ur_ros2_control_node-1] [INFO] [1709625809.219461721] [UR_Client_Library:]: Robot connected to reverse interface. Ready to receive control commands.
[ur_ros2_control_node-1] [INFO] [1709625811.348872465] [UR_Client_Library:]: Connection to reverse interface dropped.
[ur_ros2_control_node-1] [INFO] [1709625811.351471736] [UR_Client_Library:]: Robot connected to reverse interface. Ready to receive control commands.
[ur_ros2_control_node-1] [INFO] [1709625812.605244396] [UR_Client_Library:]: Connection to reverse interface dropped.

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[fmauch]

As written in other places: We aren't that familiar with how network traffic is handled on WSL2. As we are currently relying on rather strict timing constraints we encourage people to use a native Linux with a low-latency kernel.

So, I'm afraid I cannot give much more help at the time being.

[Jshulgach]

@AGuthmann this was a problem I experienced myself as well using the foxy distribution on a Jetson nano running Ubuntu 20.04. The fix for me was to uninstall the binary packages, build from source, go into the hardware_interfaces.cpp file and insert a new line to the initialization function: ur_driver_->setKeepaliveCount(500); right before ur_driver_->startRTDECommunication();.

For the foxy distibution the startup function was URPositionHardwareInterface::start().

I'm running WSL2 on a Windows 11 PC and have set up the drivers from source with a similar hard-coded modification, until I find an easy way to modify the system parameter. 500ms could be significantly longer than needed, so you can adjust accordingly.