INSTRUMENTATION & CONTROL 5. Leveraging Boolean logic. A successful new control method was developed using a single switch toggled by a Boolean derived from the measurement-to-setpoint error of the override controller. For example, when the error is in the direction that no override action is necessary (the temperature measurement is lower than the setpoint), the Boolean is false. However, when the error is just slightly in the direction that override action is desired, the Boolean becomes true. Courtesy: GenOn Energy TE Override controller Errorhttp://www.powermag.com