docs: Clarify that the motion functions use script functions for execution

Make it explicit that there is no magic going on here, but the motion
functions simply forward information to respective URScript functions
using the same parametrization and implications as the script functions.

Author: urfeex

doc/architecture/instruction_executor.rst

@@ -12,6 +12,15 @@ The Instruction Executor uses the :ref:`trajectory_point_interface` and the
 :ref:`reverse_interface`
 for sending motion instructions to the robot. Hence, it requires a :ref:`ur_driver` object.
 
+.. note::
+   The ``InstructionExecutor`` simply forwards the trajectory points to the robot. Execution
+   is done using respective URScript functions such as `movej
+   <https://www.universal-robots.com/manuals/EN/HTML/SW5_20/Content/prod-scriptmanual/G5/movej_qa14v105t0r.htm>`_
+   or `movel
+   <https://www.universal-robots.com/manuals/EN/HTML/SW5_20/Content/prod-scriptmanual/G5/movel_posea12v025t.htm>`_.
+   Therefore, all parameters and restrictions of these functions apply. For example, velocity and
+   acceleration parameters will be ignored if there is a time != 0 given.
+
 As a minimal working example, please see ``examples/instruction_executor.cpp`` example:
 
 .. literalinclude:: ../../examples/instruction_executor.cpp

doc/architecture/trajectory_point_interface.rst

@@ -17,6 +17,15 @@ control PC to the robot for execution. Execution isn't started, before a start c
 the ``ReverseInterface``. Once trajectory execution is done (either successful, failed or canceled
 externally), the robot will send a response back to the control PC via the trajectory socket.
 
+.. note::
+   The ``TrajectoryPointInterface`` simply forwards the trajectory points to the robot. Execution
+   is done using respective URScript functions such as `movej
+   <https://www.universal-robots.com/manuals/EN/HTML/SW5_20/Content/prod-scriptmanual/G5/movej_qa14v105t0r.htm>`_
+   or `movel
+   <https://www.universal-robots.com/manuals/EN/HTML/SW5_20/Content/prod-scriptmanual/G5/movel_posea12v025t.htm>`_.
+   Therefore, all parameters and restrictions of these functions apply. For example, velocity and
+   acceleration parameters will be ignored if there is a time != 0 given.
+
 
 Communication protocol
 ----------------------