DynamixelCommand Client

[NAEE09]

HI!!

I just want to use a dynamixel motor (PM42) with operanting mode: 4 (extended position control mode). I have already created a new file yaml for the dynamixel_controllers.launch, and use the command line "rosservice call /dynamixel_workbench/dynamixel_command command: ' ' .... " and it works, but I want to make a python script with a client for dynamixel_command, but It gives me an error. Maybe this is something very simple, but if you can help me, I will be very grateful!

Model Name: PM42-010-S260-R
yaml file:

dyna1:
  ID: 1
  Return_Delay_Time: 0
  Operating_Mode: 4

Client script

#!/usr/bin/env python
import rospy
from dynamixel_workbench_msgs.srv import DynamixelCommand



if __name__ == "__main__":
	rospy.init_node('set_position')
	rospy.wait_for_service('dynamixel_workbench/dynamixel_command')
	client_pos = rospy.ServiceProxy('dynamixel_workbench/dynamixel_command',DynamixelCommand)
	request = DynamixelCommand()
	request.command = ''
	request.id = 1
	request.addr_name = 'goal_position'
	request.value = 263000
	is_success = client_pos(request)

The commands I used in order

$ roslaunch dynamixel_workbench_controllers dynamixel_controllers.launch

$ rosrun my_dynamixel_tutorial control_position_spool.py 

Error message on terminal

raceback (most recent call last):
  File "/home/me/catkin_ws/devel/lib/my_dynamixel_tutorial/control_position_spool.py", line 15, in <module>
    exec(compile(fh.read(), python_script, 'exec'), context)
  File "/home/me/catkin_ws/src/my_dynamixel_tutorial/src/control_position_spool.py", line 21, in <module>
    is_success = client_pos(request)
  File "/opt/ros/noetic/lib/python3/dist-packages/rospy/impl/tcpros_service.py", line 442, in __call__
    return self.call(*args, **kwds)
  File "/opt/ros/noetic/lib/python3/dist-packages/rospy/impl/tcpros_service.py", line 498, in call
    request = rospy.msg.args_kwds_to_message(self.request_class, args, kwds) 
  File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msg.py", line 122, in args_kwds_to_message
    return data_class(*args)
  File "/home/me/catkin_ws/devel/lib/python3/dist-packages/dynamixel_workbench_msgs/srv/_DynamixelCommand.py", line 42, in __init__
    super(DynamixelCommandRequest, self).__init__(*args, **kwds)
  File "/opt/ros/noetic/lib/python3/dist-packages/genpy/message.py", line 354, in __init__
    raise TypeError('Invalid number of arguments, args should be %s' % str(self.__slots__) + ' args are' + str(args))
TypeError: Invalid number of arguments, args should be ['command', 'id', 'addr_name', 'value'] args are(<dynamixel_workbench_msgs.srv._DynamixelCommand.DynamixelCommand object at 0x7f085cec16a0>,)