Set Tool I/O with ROS2

ROS
1

I`m using ROS2 Humble and the UR_Driver.

I try to Set the Tool I/O of my UR3e.
I already figured out how to set them with the Terminal.

ros2 service call /io_and_status_controller/set_io ur_msgs/srv/SetIO "{fun: 1, pin: 17, state: 1}"

Now i try to Set them with my custom Script in my custom workspace.
I assume it has to work similar to the Client in the tutorial. But i struggle a little with what to include and how to substitude the AddTwoInts.

Can someone help me out on this?

2

Hi,

welcome to the world of ROS(2). You’ll first have to import the service definition:

from ur_msgs.srv import SetIO

The rest should be fairly straight forward

    def send_request(self, a, b):
        self.req.fun = SetIO.FUN_SET_DIGITAL_OUT # Prefer using constants instead of writing the constant's value
        self.req.pin = 17
        self.state = 1
        ...

I hope, this helps.

3

Thank you

i wrote the Client like this:

from ur_msgs.srv import SetIO
import rclpy
from rclpy.node import Node


class IOClient(Node):

    def __init__(self):
        super().__init__('client_test')
        self.cli = self.create_client(SetIO, 'set_i_o')
        while not self.cli.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('service not available, waiting again...')
        self.req = SetIO.Request()

    def send_request(self):
        self.req.fun = SetIO.FUN_SET_DIGITAL_OUT # Prefer using constants instead of writing the constant's value
        self.req.pin = SetIO.PIN_TOOL_DOUT1
        self.req.state = SetIO.STATE_ON 

        self.future = self.cli.call_async(self.req)
        rclpy.spin_until_future_complete(self, self.future)
        


def main():
    rclpy.init()

    IOclient = IOClient()
    IOclient.destroy_node()
    rclpy.shutdown()


if __name__ == '__main__':
    main()

I also added <depend>ur_msgs</depend> in package.xml
and in setup.py i added 'console_scripts': [ 'client=client_test.client_test:main'].

after colcon build and source insatll/setup.bash i run ros2 run client_test client

and get this output

Traceback (most recent call last):
  File "/home/luca/workspace/ur_control/install/client_test/lib/client_test/client", line 33, in <module>
    sys.exit(load_entry_point('client-test==0.0.0', 'console_scripts', 'client')())
  File "/home/luca/workspace/ur_control/install/client_test/lib/client_test/client", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/usr/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1004, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'client_test.client_test'
[ros2run]: Process exited with failure 1

My path looks like this: ~workspace/ur_control/src/client_test/src/client_test.py
My package is called client_test and my file is called client_test.py

4

I had to move the file to my client_test folder with my empty __init__.py in there.

Now the file is executeable but it cant connect to the service.

[INFO] [1666702583.137077628] [client_test]: service not available, waiting again...

But with

ros2 service call /io_and_status_controller/set_io ur_msgs/srv/SetIO "{fun: 1, pin: 17, state: 1}

i can set the DO.

5

This creates a service client for the service running on /set_i_o This service does not exist, since it lives in /io_and_status_controller/set_io.

Please note, that such common questions are better asked on answers.ros.org. There will be a broader audience being able to help you with your problems getting started with ROS.

6

Ok
Thank you for you help