Phidgets high speed encoder ROS driver

This is the ROS driver for Phidgets high speed encoder. The various topics, services, and parameters that the node operates with are listed below.

Topics

/joint_states (sensor_msgs/JointState) - A joint state message containing the current state of all encoders.
/joint_states_chXX_decim_speed (phidgets_msgs/EncoderDecimatedSpeed) - One topic per encoder of the decimated (average) speed reading from the encoder.

serial (int) - The serial number of the phidgets high speed encoder to connect to. If -1 (the default), connects to any high speed encoder phidget that can be found.
hub_port (int) - The phidgets VINT hub port to connect to. Only used if the high speed encoder phidget is connected to a VINT hub. Defaults to 0.
frame_id (string) - The header frame ID to use when publishing the message. Defaults to encoder_link.
speed_filter_samples_len (int) - The number of data points over which to average the speed. Defaults to 10.
speed_filter_idle_iter_loops_before_reset (int) - The number of idle loops (loops with no data) before the average speed will be reset to 0. Defaults to 1.
publish_rate (int) - How often the driver will publish data on the ROS topic. If 0 (the default), it will publish every time there is an update from the device (so at the data_interval_ms). If positive, it will publish the data at that rate regardless of the acquisition interval.