Intel 05-1832-002 User Manual

258

return the calling line Directory Number

!

!

!

! Description

The dx_gtcallid( ) function returns the calling line Directory Number (DN) sent by the Central 
Office (CO). On successful completion, a NULL-terminated string containing the caller’s phone 
number (DN) is placed in the buffer. Non-numeric characters (punctuation, space, dash) may be 
included in the number string; however, the string may not be suitable for dialing without 
modification.

Caller ID information is available for the call from the moment the ring event is generated and until 
the call is either disconnected (for answered calls) or until rings are no longer received from the CO 
(for unanswered calls). If the call is answered before caller ID information has been received from 
the CO, caller ID information will not be available.

If the call is not answered and the ring event is received before the caller ID information has been 
received from the CO, caller ID information will not be available until the beginning of the second 
ring (CLASS, ACLIP) or the beginning of the first ring (CLIP, JCLIP).

To determine if caller ID information has been received from the CO before issuing a 
dx_gtcallid( )or 

 caller ID function, check the event data in the event block. When 

the ring event is received, the event data field in the event block is bitmapped and indicates that 
caller ID information is available when bit 0 (LSB) is set to a 1. 

int dx_gtcallid (chdev, bufferp)

int chdev

valid channel device handle

unsigned char *bufferp

pointer to buffer where calling line Directory Number is returned 

0 success
-1 error return code

srllib.h
dxxxlib.h

Caller ID

synchronous

Springware 

chdev 

specifies the valid channel device handle obtained when a channel was opened 
using 

bufferp 

pointer to buffer where calling line Directory Number (DN) is returned

Note: Make sure to allocate a buffer size large enough to accommodate the 

DN returned by this function.