NAME
          irTTIntr - selectively identify touch-tones which interrupt
          speech

     SYNOPSIS
          #include <irapi.h>

          int irTTIntr ( channel_id cid, const char *tt_string, char
          *prev_tt_string);


     DESCRIPTION
          irTTIntr specifies which touch-tones can interrupt the
          current activity on the channel specified by cid.

          tt_string is a string of characters from the set
          "0123456789ABCD*#" which may cause the interrupt.  Any char-
          acter not in the string is reported (unless irTTMask is also
          used), but does not result in an interrupt.  The touch-tone
          interrupts have no effect on DTMF muting.

          The current value of the string is copied to the location
          (caller allocated) pointed to by prev_tt_string.

          Note that the event IRE_INPUT must be set with the appropri-
          ate interruption masks in order for the interrupts specified
          through irTTIntr to take effect.  Applications relying on
          irTTIntr should set IRE_INPUT to (IRF_PLAYINTR |
          IRF_SAY_INTR | IRF_RECORDINTR ) via irSetEvent to enable the
          IRE_INPUT event as an interrupt for these activities.

          If tt_string is set to point to a null string, no touch-
          tones will interrupt speech.

          If tt_string is set to 0, the string is unchanged.

          If prev_tt_string is set to 0, the previous string is not
          returned.

          The default string is the entire set "0123456789ABCD*#"
          which is set upon channel initialization.

     EVENT
          No event results from the call to irTTIntr.

     RETURN VALUE
          IRR_OK is returned on success.

          IRR_FAIL is returned on error.

     ERROR
          Upon error, irError is set as follows:
          IRER_INVALID if cid or tt_string are invalid (invalid char-
          acter or too many characters (maximum IRD_MAX_TT)),

     SEE ALSO
          irTTMask(3IRAPI)

     VERSION
          This is version 8/31/00 of this man page.