Manual push buttons:

The deviation indicator, setpoint adjustment thumbwheel, setpoint indicator, and output meter of the controller in Figure. A Function essentially the similar as those in Figure. The remaining controls and indicators are relatively different.  Thus, each will be discussed.

These buttons are situated below each end of the output meter and are used in the manual mode of operation.  A Buttons are labeled to denote their effect on the last control element. The labels are "open-close" for valves and "slow-fast" for variable speed devices. The left push button reduces the output signal. A right push button increases the output signal. Either button could be depressed at two different positions, half-in and full-in. At the half-in position, the output signal changes slowly. At the full-in position, the outcome signal changes about ten times faster.