- What is the difference between ROS topics and ROS messages?
A) Both stand for the data transmitted from one node to the other.
B) A topic is how you identify a transmission channel and a message is one sample of the content that flows through that channel.
C) Any topic name has to be unique, while several topics can transmit the same message.
- Which command would use to record a ROS session?
A) rosbag
B) rosrecord
C) roswrite
- Can a ROS node have a publisher and a subscriber at the same time?
A) Yes, if the topic subscriber is the same as the topic publisher.
B) No, because it would imply a programming conflict: a node with a publisher loops at a constant rate, that is, rate.sleep(), while a node with a subscriber only runs an iteration if it receives a message, that is, rospy.spin().
C) Yes, and the node is driven by the subscriber, that is, the node broadcasts a...
