This block samples the vector signal at its input and packs it into a ROS message of type std_msgs::Float64MultiArray. Each time the block is run by its time domain, this message is published under a given topic name.

  RosPublisherDoubleArray pubArray("myTopic", 100); // create publisher block

For ROS2 you have to pass the node, from where the topic is sent. The ROS2 message is of type std_msgs::msg::Float64MultiArray.

  RosPublisherDoubleArray pubArray(node, "myTopic", 100); // create publisher block

This block can be connected to any signal whose value is of type Matrix<N, 1, double>.
The time stamp of the signal is not transmitted.