====== ROS Subscriber Double ======
This block receives ROS messages of type ''std_msgs::Float64''. Each time the block is run by its time domain, the message content is written to the output of the block.
<code cpp>
  RosSubscriberDouble subDouble("myNode/myTopic"); // create subscriber block
</code>

For ROS2 you have to pass the node, from where the topic is received. The ROS2 message is of type ''std_msgs::msg::Float64''.
<code cpp>
  RosSubscriberDouble subDouble(node, "myNode/myTopic"); // create subscriber block
</code>

IMPORTANT The message is transmitted without time stamp. The time stamp of the signal is set to the actual time when running the block.