User's Manual

Voice API Programming Guide — June 2005 33
Application Development Guidelines
specified in the tp_flags field of the DV_TPT. When this termination condition is met, a
TM_LCOFF termination reason is returned from ATDX_TERMMSK( ).
maximum delay between digits (DX_IDDTIME)
This termination condition monitors the length of time between the digits being received. A
specific length of time can be placed in the tp_length field of a DV_TPT. If the time between
receiving digits is more than this period of time, the function terminates. The amount of time
can be specified in 100 msec units (default) or 10 msec units. 10 msec units can be specified in
the tp_flags field of the DV_TPT. When this termination condition is met, a TM_IDDTIME
termination reason is returned from ATDX_TERMMSK( ).
On DM3 boards, this termination condition is only supported by the dx_getdig( ) function.
maximum digits received (DX_MAXDTMF)
This termination condition counts the number of digits in the channel's digit buffer. If the
buffer is not empty before the I/O function is called, the digits that are present in the buffer
when the function is initiated are counted as well. The maximum number of digits to receive is
set by placing a number from 1 to 31 in the tp_length field of a DV_TPT. This value specifies
the number of digits allowed in the buffer before termination. When this termination condition
is met, a TM_MAXDTMF termination reason is returned from ATDX_TERMMSK( ).
maximum length of non-silence ((DX_MAXNOSIL)
This termination condition is not supported on DM3 boards.
Non-silence is the absence of silence: noise or meaningful sound, such as a person speaking.
This condition is enabled by setting the tp_length field of a DV_TPT to a specific period of
time. When non-silence is detected for this length of time, the I/O function will terminate. This
termination condition is frequently used to detect dial tone, or the howler tone that is used by
central offices to indicate that a phone has been off-hook for an extended period of time. The
amount of time can be specified in 100 msec units (default) or 10 msec units. 10 msec units
can be specified in the tp_flags field of the DV_TPT. When this termination condition is met, a
TM_MAXNOSIL termination reason is returned from ATDX_TERMMSK( ).
maximum length of silence (DX_MAXSIL)
This termination condition is enabled by setting the tp_length field of a DV_TPT. The
specified value is the length of time that continuous silence will be detected before it
terminates the I/O function. The amount of time can be specified in 100 msec units (default) or
10 msec units. 10 msec units can be specified in the tp_flags field of the DV_TPT. When this
termination condition is met, a TM_MAXSIL termination reason is returned from
ATDX_TERMMSK( ).
pattern of silence and non-silence (DX_PMON and DX_PMOFF)
This termination condition is not supported on DM3 boards.
A known pattern of silence and non-silence can terminate a function. A pattern can be
specified by using DX_PMON and DX_PMOFF in the tp_termno field in two separate
DV_TPT structures, where one represents a period of silence and one represents a period of
non-silence. When this termination condition is met, a TM_PATTERN termination reason is
returned from ATDX_TERMMSK( ).
DX_PMOFF and DX_PMON termination conditions must be used together. The DX_PMON
terminating condition must directly follow the DX_PMOFF terminating condition. A
combination of both DV_TPT structures using these conditions is used to form a single
termination condition. For more information, see the DV_TPT structure in the Voice API
Library Reference.