Hi all,

I'm trying to publishing to a topic but I have an absurd problem:

When I use this:
self.pub = rospy.Publisher('arm_controller/command', JointTrajectory)
msg = JointTrajectory()
self.pub.publish(msg)
it does not publish absolutly nothing.

But, if I use the pub.publish inside an infinite loop, it works:
self.pub = rospy.Publisher('arm_controller/command', JointTrajectory)
msg = JointTrajectory()
while True:
          self.pub.publish(msg)


I can publish with -rostopic pub- without problems, so it's a code problem? What I should change?

Best regards
manuel