直接数字控制在暖通空调应用中的优势之一是，积分模式等功能可以整合到软件中，而不是使用更昂贵的硬件。当使用比例积分（PI）控制时，有必要选择比例常数和积分常数的组合，以提供响应且稳定的控制。本文报道了这两个常数的不同组合的实验系统的行为。暖通空调实践中使用的阀门和阻尼器执行器通常会出现滞后现象，积分模式最终会补偿这种非线性，但本研究表明滞后补偿是可取的。当控制动作方向反转时，该过程使控制信号发生阶跃变化。引文:研讨会，ASHRAE交易，1984年，第卷。 90分。密苏里州堪萨斯城2B

One of the strengths of direct digital control in HVAC applications is that such features as the integral mode can be incorporated in software rather than using more expensive hardware. When proportional integral (PI) control is used, it is necessary to select both the proportional and integral constants in a combination that provides responsive, yet stable, control. This paper, reports the behavior, of an experimental system with various combinations of these two constants.Valve and damper actuators used in HVAC practice typically experience hysteresis and the integral mode would ultimately compensate for this non-linearity, but this study suggests the advisability of hysteresis compensation. This process makes a step change in the control signal when the direction of control action reverses.