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.
759
PID unit selection
A600
C42 (934)
PID display bias coefficient
*1
A630
C43 (934)
PID display bias analog value
*1
A631
C44 (935)
PID display gain coefficient
*1
A632
C45 (935)
PID display gain analog value
*1
A633
*1 On the LCD operation panel used as the command source, the parameter number in parentheses appears instead of that starting with the letter C.
 Calibration of PID display bias and gain (C42 (Pr.934) to C45 (Pr.935))
• When both C42 (Pr.934) and C44 (Pr.935) ≠ "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% to C42 (Pr.934) and the value that is
displayed when the PID measured value (control amount) is 100% to C44 (Pr.935).
• When both C42 (Pr.934) and C44 (Pr.935) ≠"9999" and Pr.133 is set as the set point, the setting of C42 (Pr.934) is treated
as 0%, and C44 (Pr.935) 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 282 for details, and make the necessary adjustments by considering C7 (Pr.905) as C45 (Pr.935) and Pr.126
as C44 (Pr.935).
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.
352
14.(A) Application Parameters
14.5 Calibration of PID display
Name Initial value
0
9999
20%
9999
100%
100
Bias
C42(Pr.934)
0 20
0 4
0 1
0 2
C43(Pr.934)
Setting
range
Change the unit of the PID control-related values that is
0 to 43
displayed on the LCD operation panel (FR-LU08).
9999 Without display unit switching
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
100%
20mA
Frequency setting signal
5V
10V
C45(Pr.935)
Description
Gain
C44(Pr.935)