.. _auto_drl_stop:

drl_stop (Auto Mode)
------------------------------------------
This section explains how to use :ref:`drl_stop <drl_stop>`  
during **Auto (Run)** operations to stop a currently running  
**DRL (Doosan Robotics Language)** program.

It is typically used to interrupt a task sequence triggered by ``drl_start``, allowing external systems (PC, PLC, MES, vision logic, safety logic) to control when the robot should halt DRL execution.

When drl_stop returns true, the robot is in Manual mode; call set_robot_mode(ROBOT_MODE_AUTONOMOUS) before the next drl_start. When no DRL program is running or paused, or the controller refuses the stop, drl_stop returns false and the mode does not change. drl_stop also returns false after the program has stopped when Manual mode is not confirmed or the robot is in a fault state; after a false return, check get_program_state() and get_robot_mode().

**Typical usage**

- Stop an active DRL program when a cycle must be interrupted.  
- Integrate with external UI/PLC buttons (STOP / EMERGENCY STOP substitutes).  

.. Note::

   - The program's motion is always quick-stopped.
   - ``0`` and ``1`` end the program as a normal forced stop; ``2`` ends it as an error stop.
   - The function only succeeds if a DRL program is currently running or paused.  

**Example: Stopping a Running DRL Task**

.. code-block:: cpp

   // 1) Check DRL program execution state
   DRL_PROGRAM_STATE state = drfl.get_program_state();

   // 2) Stop only if the program is running or paused
   if (state == DRL_PROGRAM_STATE_PLAY ||
       state == DRL_PROGRAM_STATE_HOLD) {

       // STOP_TYPE_QUICK (1): normal forced stop
       if (!drfl.drl_stop(STOP_TYPE_QUICK)) {
           printf("Failed to stop DRL program.\n");
           return -1;
       }

       printf("DRL program stopped.\n");
   } else {
       printf("No active DRL program.\n");
   }

In this example, the program checks the current DRL execution state and stops the program only when a DRL program is running or paused. This allows external logic to interrupt automatic task sequences.

**Tips**

- Combine with :ref:`drl_pause <auto_drl_pause>` for smoother step-wise control.  
- Log stop reasons (sensor trigger, operator request, safety event) for debugging and traceability.