dx_RxIottData( )

Description | Cautions | Example | Errors | See Also

Name:	int dx_RxIottData(chdev, iottp, lpTerminations, wType, lpParams, mode)
Inputs:	int chdev	valid channel device handle
	DX_IOTT *iottp	pointer to I/O transfer table
	DV_TPT *lpTerminations	pointer to termination parameter table
	int wType	data type
	LPVOID lpParams	pointer to data type-specific information
	int mode	function mode
Returns:	0 if successful -1 if error
Includes:	dxxxlib.h srlib.h
Mode:	Synchronous/asynchronous

Description

The dx_RxIottData( ) function is used to receive data on a specified channel. The data may come from any combination of data files, memory, or custom devices. The wType parameter specifies the type of data to be received, for example ADSI data.

After dx_RxIottData( ) is called, data reception continues until one of the following occurs:

• dx_stopch( ) is called
• the data requirements specified in the DX_IOTT are fulfilled
• the channel detects end of FSK data
• one of the conditions in the DV_TPT is satisfied

If the channel detects end of FSK data, the function is terminated and ATDX_TERMMSK( ) will return TM_EOD as the cause of termination.

Upon asynchronous completion of dx_RxIottData( ), the TDX_RXDATA event is posted.

Parameter	Description
chdev:	The valid Dialogic channel device handle.
iottp:	The pointer to the I/O Transfer Table. The iottp parameter specifies the destination for the received data. This is the same DX_IOTT structure used in dx_playiottdata( ) and dx_reciottdata( ).
lpTerminations:	The pointer to the Termination Parameter Table.
wType:	Specifies the type of data to be received. To receive ADSI data, set wType to DT_ADSI. NOTE: This parameter also can be set to DT_RAW to receive binary data at 64Kbit/sec.
lpParams:	The pointer to information specific to the data type specified in wType. The format of the parameter block depends on wType. For ADSI data, set lpParams to point to an ADSI_XFERSTRUC structure.
mode:	Specifies how the function should execute, either EV_ASYNC (asynchronous) or EV_SYNC (synchronous).

Cautions

Library level data is buffered when it is received. Applications can adjust the size of the buffers to address buffering delay. The DXCH_RXDATABUFSIZE channel parameter can be used with the dx_setparm( ) and dx_getparm( ) functions to adjust the buffer size.

Example

// Synchronous receive ADSI data  
DX_IOTT iott = {0};  
char *devnamep = "dxxxB1C1";  
char buffer[16];  
ADSI_XFERSTRUC adsimode;  
DV_TPT tpt;  
int chdev;  
         .  
         .  
         .  
    sprintf(buffer, "RECEIVE.ADSI");  
    if ((iott.io_fhandle = dx_fileopen(buffer, O_BINARY)) == -1) {  
         /* Perform system error processing */  
         exit(2);  
    }  
    if ((chdev = dx_open(devnamep, 0)) == -1) {  
         fprintf(stderr, "Error opening channel %s\n",devnamep);  
         dx_fileclose(iott.io_fhandle);  
         exit(1);  
    }  
         .  
         .  
         .
  
    // destination is a file  
    iott.io_type = IO_DEV|IO_EOT;  
    iott.io_bufp = 0;  
    iott.io_offset = 0;  
    iott.io_length = -1;  
    adsimode.cbSize = sizeof(adsimode);  
    adsimode.dwRxDataMode = ADSI_NOALERT;  
    printf("Waiting for incoming ring\n");  
    dx_wtring(chdev, 2, DX_OFFHOOK, -1);  
    // Specify maximum time termination condition in the TPT.  
    // Application specific value is used to terminate dx_RxIottData( )  
    // if end of data is not detected over a specified duration.  
    tpt.tp_type = IO_EOT;  
    if (dx_clrtpt(&tpt, 1) == -1) {  
       // Process error  
    }  
    tpt.tp_termno = DX_MAXTIME;  
    tpt.tp_length = 1000;  
    tpt.tp_flags = TF_MAXTIME;  
    if (dx_RxIottData(chdev, &iott, NULL, DT_ADSI, &adsimode, EV_SYNC) < 0) {  
         fprintf(stderr, "ERROR: dx_TxIottData failed on Channel %s; error:  
              %s\n", ATDV_NAMEP(chdev), ATDV_ERRMSGP(chdev));  
    }  
         .  
         .  
         .

Errors

If the function returns -1 to indicate an error, use the SRL Standard Attribute function ATDV_LASTERR( ) to obtain the error code or you can use ATDV_ERRMSGP( ) to obtain a descriptive error message.

Possible error codes from the dx_RxIottData( ) function include the following:

Error Code	Description
EDX_BADPARM	Invalid data mode
EDX_BADIOTT	Invalid DX_IOTT (pointer to I/O transfer table)
EDX_BUSY	Channel already executing I/O function
EDX_SYSTEM	Error from operating system; use dx_fileerrno( ) to obtain error value

See Also

• dx_TxIottData( )
• dx_TxRxIottData( )

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