For the machine rotation angles Gantry Angle (300A,011E), Beam Limiting Device Angle (300A,0120), Patient Support Angle (300A,0122) , and Table Top Eccentric Angle (300A,0125), rotation direction is specified as clockwise (CW), counter-clockwise (CC), or NONE. The maximum permitted rotation between two Control Points is 360 degrees. Examples:
a) Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = NONE:
b) Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = CW:
Full clockwise rotation (360 degrees).
c) Table Angle moves from 170 degrees to 160 degrees, Table Rotation Direction = CC:
Counter-clockwise rotation by 350 degrees (note direction of increasing table angle as defined by IEC 61217).