dx_unlistenecr( )

Description | Cautions | Example | Errors | See Also

Name:	int dx_unlistenecr(chdev)
Inputs:	int chdev	voice channel device handle
Returns:	0 on success
	-1 on error
Includes:	dxxxlib.h
Category:	Echo Cancellation Resource
Mode:	Synchronous

Description

The dx_unlistenecr( ) function disables ECR mode echo cancellation on the voice channel and sets the channel back into Standard Voice Processing (SVP) mode echo cancellation.

NOTE:

Calling the dx_listenecr( ) or dx_listenecrex( ) function to connect to a different SCbus time slot automatically breaks an existing connection. Thus, when changing connections, you do not need to call the dx_unlistenecr( ) function.

Parameter	Description
chdev	Specifies the voice channel device handle obtained when the channel was opened using dx_open( ).

Cautions

This function fails when:

• An invalid channel device handle is specified.
• The ECR feature is not enabled on the board specified.
• The ECR feature is not supported on the board specified.

Example

#include <stdio.h>  
#include <windows.h>  
#include <srllib.h>  
#include <dxxxlib.h>  
main()  
{  
   int chdev;   /* Voice Channel device handle */  
                /* Open board 1 channel 1 device */  
   if ((chdev = dx_open("dxxxB1C1", 0)) == -1) {  
       /* Perform system error processing */  
       exit(1);  
   }  
   /* Disconnect echo-reference receive of board 1, channel 1 from the SCbus, and stop   
   
      the ECR feature */  
   if (dx_unlistenecr(chdev) == -1) {  
       printf("Error message = %s", ATDV_ERRMSGP(chdev));  
       exit(1);  
   }  
   return(0);  
}

Errors

If the function returns -1, use the SRL Standard Attribute function ATDV_LASTERR( ) to obtain the error code or use ATDV_ERRMSGP( ) to obtain a descriptive error message. One of the following error codes may be returned:

Equate	Returned When
EDX_BADPARM	Parameter error
EDX_SH_BADCMD	Function is not supported in current bus configuration
EDX_SH_BADEXTTS	SCbus time slot is not supported at current clock rate
EDX_SH_BADINDX	Invalid Switch Handler index number
EDX_SH_BADLCLTS	Invalid channel number
EDX_SH_BADMODE	Function not supported in current bus configuration
EDX_SH_BADTYPE	Invalid channel type (voice, analog, etc.)
EDX_SH_CMDBLOCK	Blocking function is in progress
EDX_SH_LCLDSCNCT	Channel already disconnected from SCbus
EDX_SH_LIBBSY	Switch Handler library busy
EDX_SH_LIBNOTINIT	Switch Handler library uninitialized
EDX_SH_MISSING	Switch Handler is not present
EDX_SH_NOCLK	Switch Handler clock fallback failed
EDX_SYSTEM	Error from operating system; use dx_fileerrno( ) to obtain error value

See Also

• dx_listen( )
• dx_listenecrex( )

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