blokeeriva kaitsepiire erivorm, mis suletud asendisse jõudes annab käsu masina ohtliku (ohtlike) talitlus(t)e alustamiseks ilma käivituspidet eraldi kasutamata, special form of interlocking guard which, once it has reached its closed position, gives a command to initiate the hazardous machine function(s) without the use of a separate start control