Calibration Of Pid Display - Mitsubishi Electric 800 Series Instruction Manual

14.5

Calibration of PID display

When the operation panel is used, the display unit of parameters and monitor items related to PID control can be changed to
various units.
Pr.
C42
PID display bias coefficient
A630
C43
PID display bias analog value
A631
C44
PID display gain coefficient
A632
C45
PID display gain analog value
A633
 Calibration of PID display bias and gain (C42 to C45)
• When both C42 and C44 ≠ "9999", the bias and gain values for the set point, measured value and deviation in PID control
can be calibrated.
• "Bias"/"gain" function can adjust the relation between PID displayed coefficient and measured value input signal that is
externally input. Examples of these measured value input signals are 0 to 5 VDC, 0 to 10 VDC, or 4 to 20 mADC. (The
terminals used for measured value input can be selected at Pr.128, Pr.609, Pr.610.)
• Set the value that is displayed when the PID measured value (control amount) is 0% in C42 and the value that is displayed
when the PID measured value (control amount) is 100% in C44.
• When both C42 and C44 ≠"9999" and Pr.133 is set as the set point, the setting of C42 is treated as 0%, and C44 as 100%.
• There are three methods to adjust the PID display bias/gain.
Method to adjust any point by application of a current (voltage) to the measured value input terminal
Method to adjust any point without application of a current (voltage) to the measured value input terminal
Method to adjust only the display coefficient without adjustment of current (voltage)
(Refer to page 273 for details, and make the necessary adjustments by considering C7 as C45 and Pr.126 as C44.)
NOTE
• Always calibrate the input after changing the voltage/current input specification with Pr.73 and Pr.267, and the voltage/current
input selection switch.
342
14. (A) Application Parameters
14.5 Calibration of PID display
Name Initial value
9999
20%
9999
100%
100
Bias
C42
0 20
0 4
Frequency setting signal
0 1
0 2
C43
Setting
range
Set the coefficient of the bias side (minimum) of measured value
0 to 500
input.
9999 Displayed in %.
Set the converted % of the bias side (minimum) current/voltage
0% to 300%
of measured value input.
Set the coefficient of the gain side (maximum) of measured value
0 to 500
input.
9999 Displayed in %.
Set the converted % of the gain side (maximum) current/voltage
0% to 300%
of measured value input.
Initial value
Gain
C44
100%
20mA
5V
10V
C45
Description