Hi,
can some body help me in explaining the what is the "EXT BAS" in Declaration section of the following program example. 
;------- Declaration section -------
EXT BAS (BAS_COMMAND :IN,REAL :IN )
DECL AXIS HOME ;Variable HOME of type AXIS
DECL FRAME BASE1 ;Variable BASE1 of type FRAME
;----------- Initialization ----------
BAS (#INITMOV,0 ) ;Initialization of velocities,
;accelerations, $BASE, $TOOL, etc.
HOME={AXIS: A1 0,A2 -90,A3 90,A4 0,A5 0,A6 0}
BASE1={FRAME: X 300,Y -100,Z 0,A 90,B 0,C 0}
;----------- Main section ----------
PTP HOME ;BCO run
; Motion relative to the $BASE coordinate system
PTP {POS: X 540,Y 630,Z 1500,A 0,B 90,C 0,S 2,T 35}
; Motion relative to the $BASE-CS offset by BASE1
PTP BASE1:{POS: X 540,Y 630,Z 1500,A 0,B 90,C 0,S 2,T 35}
PTP HOME
END
