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MCQ on Building Controls IV: Two Position and Floating Responses | Primo Engineering

Ahmed Amin
اخر تحديث :
Which of the following statements, regarding the two position control response, are true?

  • A two-position control response is the simplest kind of response that can be made from a controller.
  • When a certain condition is met, the controller enables a digital output to be turned “on”.
  • When a second certain condition is met, the controller disables that digital output, or turns it “off.”
  • All of the above
  • None of the above


What is the definition of the "differential"?


  • The differential is the difference between the setting at which the controller operates at one position, and the setting at which it changes to the other position.
  • The differential is the range of inputs for which the controller output does not change, even if the input changes.
  • The differential is either on or off, 1 or 0, yes, or no…nothing in between.
  • None of the above


Imagine a temperature control system with a differential of 3 degrees. What would occur if the actual value was 1 degree warmer than the setpoint?


  • The system would supply warm air to the zone
  • The system would supply cool air to the zone
  • Nothing
  • None of the above


Why is it important to have a "neutral zone" (or "deadband") when employing a floating control system?

  • A “neutral zone” or “deadband” ensures that the system operator can decide whether or not to accept a request from a user.
  • A “neutral zone” or “deadband” ensures control devices from different manufacturers are compatible.
  • A “neutral zone” or “deadband” ensures the actuator does not respond when the actual value is within an acceptable range of the setpoint — avoiding overuse.
  • None of the above


Stability is achieved when the control point is within the throttling range.

  • True
  • False


Floating control may be used to control an analog device. The process will increase or decrease the control signal to the device based on its current position and its operating range. When floating control is used to control an analog device, the signal will be a value within a range, for example, between 0% and 100%.

  • True
  • False


What is the chief benefit of floating control?

  • Greater complexity—but more efficiency in a system
  • Greater simplicity in a system
  • Greater stability in a system
  • All of the above
  • None of the above


The throttling range is the range of inputs that translate into the full range of travel of the actuator.

  • True
  • False


What are the effects of selecting a small or large deadband?

  • A small deadband helps to keep the system close to setpoint. A large deadband improves stability.
  • A small deadband defines a tight tolerance to setpoint. A large deadband helps to prevent the system from “hunting” and making many small adjustments while trying to achieve the setpoint.
  • With a small deadband, actuators will tend to make more adjustments to maintain actual values close to setpoint and will wear out more quickly. With a large deadband actuators will operate less and their life is increased
  • All of the above
  • None of the above


The neutral zone is the range over which the output of the controller remains constant as the input varies.

  • True
  • False

Summary of Building Controls IV: Two Position and Floating Responses


A Two-Position control response is the simplest kind of response that can be made from a controller. This is simple on – off control. When a certain condition is met, the controller enables a digital output to be turned ―on‖. When a second certain condition is met, the controller disables that digital output, or turns it off. A differential is the difference between the setting at which the controller operates at one position, and the setting at which it changes to the other position.

Building Controls IV: Two Position and Floating Responses

Floating control is used to create greater stability in a system. If the value is in an acceptable range, it shouldn’t be touched! Stability is needed to avoid constant changing of equipment. Within the neutral zone, the controller output does not change, even if the input changes. The output changes only in response to an input outside the neutral zone range.

The throttling range is the range of inputs that translate into the full range of travel of the actuator.


معلومات ومصطلحات مهمة لفهم كورس الكنترول
  • ما هو actuator مشغل : الة تستخدم لتحريك جزء صغير او محرك صغير
  • شرح VAV box : نوع من انظمة التبريد والتدفئة وعند درجة حرارة معينة يختلف تدفق الهواء باختلاف انظمة التبريد الاخري
  • معني damper خانق الهواء  : هو صمام او شبكة تنظم تدفق الهواء داخل قنوات التبريد والتكيف
  • فاير دامبر Fire damper : هي منتجات تستخدم في قنوات التبريد والتدفئة للحماية من نشوب اب حريق
  • deadband النظاق الميت : هو نظاق يكون فيه الخرج بيساوي صفر بعيدا عن نظاق قيم ادخال دالة التحويل في انظمة الكنترول او الاشارات
  • ما هو throttling : هو خنق نطاق معين بغرض تقليل سرعته مثلا   




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