DLN-series adapters allow you to control LEDs’ behavior by defining the value of the DLN_LED_STATE type defined in the dln_led.h file.The list of its possible LED states is given in the following table:

To specify a LED state, use the DlnLedSetState() function. You can check the current state of a LED by using the DlnLedGetState() function.

This example shows how to manipulate LEDs on the DLN-series adapters. You can find the complete example in the “..\Program Files\Diolan\DLN\examples\c_cpp\examples\simple” folder after DLN setup package installation.

C/C++

#include "..\..\..\common\dln_generic.h"
#include "..\..\..\common\dln_led.h"
#pragma comment(lib, "..\\..\\..\\bin\\dln.lib")


int _tmain(int argc, _TCHAR* argv[])
{
	// Open device
	HDLN device;
	DlnOpenUsbDevice(&device);

	// Set LED1
	DlnLedSetState(device, 0, DLN_LED_STATE_FAST_BLINK);
	// Set LED2
	DlnLedSetState(device, 1, DLN_LED_STATE_TRIPLE_BLINK);

	// Close device
	DlnCloseHandle(device);
	return 0;
}

• Line 1:

  The dln_generic..h header file declares functions and data structures for the generic interface. In current example this header is used to call DlnOpenUsbDevice() and DlnCloseHandle() functions.

• Line 2:

  The dln_led.h header file declares functions and data structures for the LED interface. In current example this header is used to to call DlnLedSetState() function.

• Line 3:

  Use dln.lib library while project linking.

• Line 10:DlnOpenUsbDevice(&device);

  The function establishes the connection with the DLN adapter. This application uses the USB connectivity of the adapter. For additional options, refer to the Device Opening & Identification section.

• Line 13:DlnLedSetState(device, 0, DLN_LED_STATE_FAST_BLINK);

  Set LED 0 to fast blink state. You can read more about available LED states at LED States section.

• Line 15:DlnLedSetState(device, 1, DLN_LED_STATE_TRIPLE_BLINK);

  Set LED 1 to triple blink state.

• Line 18:DlnCloseHandle(device);

  The application closes the handle to the connected DLN-series adapter.

This section describes the LED functions. They are used to control and monitor the LED module of a DLN-series adapter.

Actual control of the device is due to use of commands and responses. Each function utilizes respective commands and responses. You can send such commands directly if necessary.

DlnLedGetCount()

Retrieves the total number of user-controlled LEDs

DlnLedSetState()

Configures the LED state.

DlnLedGetState()

Retrieves the current LED state.

All the functions are declared in the dln_led.h file.