NIO CommKit Host Interface Installation and System Administration Manual

DKLEVELD(3X) DKLEVELD(3X))
E-53 CommKit Host Interface, Release 4.0
NAME
dkleveld, dkeof, dkbreak, dkusb, isdkleveld, isdkeof, isdkclosed – data switch Level–D and unsequenced data
support routines
SYNOPSIS
#include <sys/types.h>
#include <dkit/rdfp.h>
#include <dkit/dk_urp.h>
int dkleveld(fd, msg, len)
int fd;
dk_lvld_t *msg;
int len;
int dkeof(fd)
int fd;
int dkbreak(fd)
int fd;
int dkusb(fd, byte1, byte2)
int fd;
uchar_t byte1;
uchar_t byte2;
int isdkleveld(fd)
int fd;
int isdkeof(fd)
int fd;
int isdkclosed(fd)
int fd;
DESCRIPTION
The host interface subroutine library contains a number of routines to support the use of AT&T data switch
URP Level–D control codes and the transmission of unsequenced data. These routines are used internally by
the host interface administrative and applications programs.
dkleveld transmits a msg of arbitrary len containing mixed URP Level–D control codes and data on the circuit
associated with fd. The mixed control and data message is scheduled for transmission after any data already
queued for the circuit. msg should point to an array of dk_lvld_t objects containing the mixed control and
data, and len is expected to be the length of the array in bytes. Each data item in the array must be made with
the dkDmkdata() macro and each control code item must be made with dkDmkctl(). The length of msg may
not exceed the system limit for control messages. A non-zero value is returned on successful completion.
dkeof transmits a URP Level–D EOF control code on the circuit associated with fd by making an internal call
to dkleveld. The EOF control code is scheduled for transmission in a separate URP block after any data
already queued for the circuit. A non-zero value is returned on successful completion.
dkbreak transmits a URP Level–D BREAK control code on the circuit associated with fd by making an
internal call to dkleveld. The BREAK control code is scheduled for transmission in a separate URP block after
any data already queued for the circuit. A non-zero value is returned on successful completion.
dkusb transmits two bytes of unsequenced data on the circuit associated with fd. The unsequenced data is
scheduled for the next transmission opportunity on the circuit, bypassing any data already queued for the
circuit. A non-zero value is returned on successful completion.