The desired value of the process variable is called the ______.

The desired value of the process variable is referred to as the set point. In control systems, the set point is the target value that a control system aims to maintain within a process. It represents the ideal level or target state for the variable being controlled, such as temperature, pressure, or flow rate.

When a control system operates, it constantly compares the actual value of the process variable (often derived from the measurement signal) to the set point. If there is any deviation, the control system may take action to adjust the process in order to bring the variable back to its desired level. This concept is essential in control theory and practice, as it defines the goal of the control process.

The other terms, such as measurement signal, controlled variable, and output signal, represent different aspects of the control system but do not directly denote the desired state. The measurement signal refers to the actual value read from sensors; the controlled variable is another term for the process variable itself; and the output signal is the control action taken by the control system in response to discrepancies between the set point and the process variable.