Implementing Control with a Backup Function

Load devices are sometimes used when evaluating (measuring) DUT performance. Depending on the parameter being evaluated, multiple controllers can be employed to control the performance of the load device, but there are also times when the load device uses only one actuator. Such cases call for wiring of a system with a switched input mechanism to the actuator.

The following is an example in which control output from 2 controllers is switched as needed, and intake control is performed by a single actuator.

Implementing control with a backup function 

Overview

  • The first controller performs temperature control using the temperature of the water from the DUT as a criterion.
  • The second controller performs heating control using the energy consumed in the load device as a criterion.
  • These controllers are separate, but the actuator at the load device is the same.

By using the control mode with backup function that comes standard with the UT55A UTAdvanced® Digital Indicating Controller, we can switch 2 outputs as necessary and rely on only one actuator for the intake control. Control output computed from temperature control is input to the UT55A (controller 2) and output as-is for control of the actuator. The control output signal to the actuator computed from heating control is output on a circuit switched by the contact input to the UT55A.

Heating control by the UT55A requires the acquisition of heat as measured values. Because it can acquire up to 4 points of analog input (direct input of temperature takes up to 2 points), the UT55A inputs the temperature of the water that passed through the DUT (A), and the temperature of the water that passed through the heat exchanger (B). It combines these temperature values with flow values and performs calculations using a UT55A ladder program such as the following.

【Ladder Program Calculation Example】

PV = (B - A) × flow × constant

A: Water temperature from DUT (A)
B: Water temperature from heat exchanger (B)
Flow: Flow value of water passing the heat exchanger
Constant: Correction value for calculation

相关产品&解决方案

UT35A/UT32A

UT35AUT32A温度控制器采用易读的14段大型彩色LCD显示屏,并配以导航键,从而极大地提升了监视和操作性能。标配梯形图顺控功能。控制器安装深度较短,有助于节省仪表面板的空间。UT35A/UT32A还支持以太网通信等开放网络。

中级UT55A/UT52A

UT55AUT52A温度控制器采用易读的14段大型彩色LCD显示屏,并配以导航键,从而极大地提升了监视和操作性能。标配梯形图顺控功能。控制器安装深度较短,有助于节省仪表面板的空间。UT55A/UT52A还支持以太网通信等开放网络。

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