The guide buttons on the handset and the `arrow' buttons at the top left-hand corner of the SCP have identical functions. Those on the handset are ostensibly dual-pressure, but the first pressure has been disabled on grounds of unreliability.
Selection between the SET, GUIDE and INCREMENT modes is made with the buttons at the bottom left-hand side of the Control Desk. The SET and GUIDE modes give continuous motion while INC moves the telescope in steps.
The set and guide rates and incremental step size can be defined at the User
Interface withe the HANDSET command (see chapter 
). Enter
new values with:
HA/S set-rate (/sec)
HA/G guide-rate (/sec)
HA/I increment ()
However the new value will only become active after the SET, GUIDE or INC button is pressed.