hil_task_stop :: Quanser C Functions

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hil_task_stop

Stops a running task.

Description

The hil_task_stop function stops a task that is running. A task may be stopped before it has processed all of its samples. Tasks may also be restarted using the hil_task_start function.

Prototype

t_error
hil_task_stop(t_task task);

Parameters

t_task task

A handle to the task, as returned by one of the task creation functions.

Return value

The return value is 0 if the task is stopped successfully. Otherwise a negative error code is returned. Error codes are defined in quanser_errors.h. A suitable error message may be retrieved using msg_get_error_message.

Error codes

QERR_HIL_TASK_STOP_NOT_SUPPORTED

This function is not supported by the board-specific HIL driver for this board type.

QERR_INVALID_TASK_HANDLE

An invalid task handle was passed as an argument. Once a task has been deleted using hil_task_delete the task handle is invalid.

QERR_INVALID_OPERATION_HANDLE

An invalid operation handle was passed as an argument to the board-specific HIL driver. Once a task has been deleted using hil_task_delete the operation handle is invalid.

QERR_DRIVER_INCOMPATIBLE_WITH_BOARD_DLL

The board-specific HIL driver passed an invalid parameter to the operating system specific kernel-level driver for the board. The board-specific HIL driver is likely not compatible with the operating system specific kernel-level driver for the board. Make sure both are up-to-date and compatible versions.

Requirements

Include Files	Libraries
hil.h	hil.lib;quanser_runtime.lib;quanser_common.lib

Examples


/*
* Reads 5000 samples at 1 kHz from the first four analog input channels, using SYSTEM_CLOCK_1.
* Return values are ignored for simplicity.
*/

t_uint32 channels[]        = { 0, 1, 2, 3 };
t_double frequency         = 1000;
t_uint32 samples           = 5000;
t_uint32 samples_in_buffer = frequency;
t_uint32 samples_to_read   = 1;

static t_double buffer[4];
t_task task;

hil_task_create_analog_reader(board, samples_in_buffer, channels, ARRAY_LENGTH(channels), &task);
hil_task_start(task, SYSTEM_CLOCK_1, frequency, samples);
for (int index = 0; index < samples; index += samples_to_read) {
    hil_task_read_analog(task, samples_to_read, buffer);
    ...
}
hil_task_stop(task);
hil_task_delete(task);

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