vlan_alive(3)

NAME
     vlan_alive - see if connected to VLAN device

C SYNOPSIS
     #include <vlan.h>

     int vlan_alive(VLAN_DEV *vlanptr);

DESCRIPTION
     Determines whether a VLAN device is connected to the serial port. The
     routine send a CR and waits an appropriate amount of time. If no CR is
     returned then there is no VLAN device connected. If a CR is returned, the
     ID command is issued to determine whether the VLAN device is NTSC or PAL
     format. If the id string ends with an 'N' then it is NTSC format. If the
     string ends with a 'P' it is PAL format.

PARAMETERS
     Name        Type        I/O     Description
     vlanptr     VLAN_DEV *   I      Pointer to vlan device

DIAGNOSTICS
     A -1 is returned if an error occurs. Otherwise one of the following
     values will be returned:

     VLAN_NOTRUNNING
            No VLAN device present

     VLAN_NTSC
            NTSC format VLAN device

     VLAN_PAL
            PAL format VLAN device

     VLAN_UNKNOWN
            VLAN present, unknown format