dx_getparm( )

Description | Cautions | Example | Errors | See Also

Name:	int dx_getparm(dev,parm,valuep)
Inputs:	int dev	valid Dialogic channel or board device handle
	unsigned long parm	parameter type to get value of
	void *valuep	pointer to variable for returning parameter value
Returns:	0 if success
	-1 if failure
Includes:	srllib.h
	dxxxlib.h
Category:	Configuration

Description

The dx_getparm( ) function returns the current parameter settings for an open device. dx_getparm( ) can only obtain the value of one parameter at a time. The channel must be idle (i.e., no I/O function running) when calling dx_getparm( ).

The function parameters are defined as follows:

Parameter	Description
dev	specifies the valid Dialogic device handle obtained when a board or channel was opened using dx_open( ).
parm	specifies the define for the parameter type whose value is to be returned in the variable pointed to by valuep.
	Board and channel parameter defines, defaults and descriptions are listed in Chapter 6. Voice Device Parameters.
valuep	points to the variable where the value of the parameter specified in parm should be returned.
NOTE: You must use a void* cast on the returned parameter value, as demonstrated in the example code for this function. valuep should point to a variable large enough to hold the value of the parameter. Refer to Chapter 6. Voice Device Parameters and to the DXBD_ and DXCH_ defines in the dxxxlib.h file. The size of a parameter is encoded in the define for the parameter. The defines for parameter sizes are PM_SHORT, PM_BYTE, PM_INT, PM_LONG, PM_FLSTR (fixed length string), and PM_VLSTR (variable length string). Most parameters are of type short.

Cautions

We highly recommend that you clear the variable the parameter value is returned to prior to calling dx_getparm( ), as illustrated in the example below. The variable whose address is passed to should be of a size sufficient to hold the value of the parameter. See the function description for more information.

Example

#include <stdio.h>  
#include <srllib.h>  
#include <dxxxlib.h>  
#include <windows.h>  
   
main()  
{  
   int bddev;  
   unsigned short parmval;  
   
   /* open the board using dx_open( ). Obtain board device descriptor in  
    * bddev  
    */  
   if ((bddev = dx_open("dxxxB1",NULL)) == -1) {  
     /* process error */  
   }  
   
   parmval = 0;    /* CLEAR parmval */  
   
   /* get the number of channels on the board. DXBD_CHNUM is of type  
    * unsigned short as specified by the PM_SHORT define in the definition  
    * for DXBD_CHNUM in dxxxlib.h. The size of the variable parmval is  
    * sufficient to hold the value of DXBD_CHNUM.  
    */  
   if (dx_getparm(bddev, DXBD_CHNUM, (void *)&parmval) == -1) {  
     /* process error */  
   }  
   
   printf("\nNumber of channels on board = %d",parmval);  
   .  
   .  
}

Errors

If this function returns -1 to indicate failure, use ATDV_LASTERR( ) and ATDV_ERRMSGP( ) to retrieve one of the following error reasons:

EDX_BADPARM	Invalid Parameter
EDX_SYSTEM	Error from operating system; use dx_fileerrno( ) to obtain error value
EDX_BUSY	Channel is busy (when channel device handle is specified) or first channel is busy (when board device handle is specified)

See Also

• dx_setparm( )

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