PID ActiveX Control

Properties

About Action BackColor
Gain Measured Mode
MVColor MVTickColor OPColor
OPMode OPTickCOlor Output
Poll Preact Reset
Setpoint SPColor SPMax
SPMin SPTickColor

 

About

Displays the about dialog box for the Proportional-Integral-Derivative (PID) control.
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Action

Changes the current operating mode of the PID control:

  0-Stop
  1-Run
  2-Reset.

Reset causes all values stored in the controller to be reset to their controller startup settings. The control must be in the RUN mode to perform calculations internally.
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BackColor

Sets the background color of the control.
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Gain

Sets The sensitivity of the controller. This value is multiplied times the difference between the setpoint and measured value, then divided by difference between the maximum and Minimum control values (the range of the controller). The value is expressed as a percentage, so 100 will cause a 50% output when the difference between measured value and setpoint is 1 half of the span of the controller (100 degrees).
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Measured

Position of the measured value arrow. The maximum value for this property is determined by the setting of the SPMax property. The minimum value is determined by the SPMin property. You usually set this value by periodically getting a measured value from a hardware I/O controller, converting the value to the range of the controller (as determined by the SPMin and SPMax properties), and then setting this property.
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Mode

Manual(0) or Automatic(1). If set to automatic, the controller calculates and sets the output value based on the measured value and setpoint. If set to manual, the controller does not adjust the output, but allows you to set it manually. Setting the mode to manual also allows you to write your own algorithms for controlling the output based on the measured value and setpoint.
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MVColor

Color of the measured value arrow.
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MVTickColor

The color of the tick marks for the measured value.
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OPColor

Color of the output arrow.
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OPMode

Normal or Reverse. In reverse mode the output is set to 100% when the measured value is greater than the setpoint. In normal mode, the output is zero when the measured value is over the setpoint. This is useful for controlled devices that work in opposite fashions. For example, some pneumatic valves are closed at 100% output and wide open at 0% output. Other valves are the opposite of this.
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OPTickColor

Color of the tick marks on the output scale.
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Output

The current output value of the controller. This value is calculated and then updated by the controller based on the control settings when the Mode property is set to Automatic. Although you can set the Output property when the controller is running, it will be overridden by the controller when it performs its next update. If the Mode property is set to Manual, then you can set the Output property to whatever you want and the controller will not change it. The range of values is 0 - 100%. You can specify a decimal value.
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Poll

Controller update period (in milliseconds). This value should be set to something reasonable (1000 milliseconds = 1 second). Setting it too low will cause the control to take a large amount of CPU time.
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Preact

This value determines how many minutes the controller "looks ahead" to determine how the output should be adjusted. The calculation is done by extrapolating from the previous measured value to determine what the value will be at the specified lead time. This setting affects the ability of the controller to respond ahead of time to rapid changes in the measured value.
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Reset

The number of times per minute that the normal output calculated based on the Gain is reapplied to the output. This setting affects the ability of the controller to correct for a continuous offset between the setpoint and measured value.
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Setpoint

Current setpoint position. This must be a value between or including the current minimum and maximum values of the controller.
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SPColor

Color of the setpoint arrow.
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SPMax

Maximum value for the setpoint.
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SPMin

Minimum value for the setpoint.
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SPTickColor

Color of the setpoint tick marks.
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Events

Measured(ByVal NewVal As Long)

Sent when the measured value changes. NewVal is the new value.
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Output(ByVal NewVal As Long)

Sent when the output value changes. NewVal is the new value.
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Setpoint(ByVal NewVal As Long)

Sent when the setpoint value changes. NewVal is the new value.
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Northeast Data Corp
Charlotte, NC 
nedatacorp@carolina.rr.com