To define the offset(s) type at the User Interface:
AP(ERTURE)/A x-value y-value
or
AP(ERTURE)/B x-value y-value
The x and y values are given in arcsec.
In order to introduce the offset, press the BEAMSWITCH A or
B button on the Control Desk; to return to the reference position,
press the NOM button. The offsets are displayed on
the Information Display.
