Mitsubishi Electric 800 Series Instruction Manual (Function page 431

 Calibration example
(Adjust room temperature to 25°C by PID control using a detector that outputs 4 mA at 0°C and 20 mA at 50°C.)
Start
Determination of set point
Determine the set point of what is
desired to be adjusted.
Conversion of set point into %
Calculate the ratio of the set point to
the detector output.
Make calibration.
Setting of set point
Input a voltage across terminals 2-5
according to the set value %.
Operation
Set the proportional band (Pr. 129)
to a slightly larger value, the integral
time (Pr. 130) to a slightly longer
time, and the differential time (Pr.
134) to "9999" (no function), and turn
ON the start signal.
Is the set point stable?
No
Parameter adjustment
To stabilize the measured value, change
the proportional band (Pr. 129) to a larger
value, the integral time (Pr. 130) to a
slightly longer time, and the differential
time (Pr. 134) to a slightly shorter time.
Adjustment end
*1 When calibration is required
Calibrate the detector output and set point input by Pr.125, C2 (Pr.902) to C4 (Pr.903) (terminal 2) or Pr.126, C5 (Pr.904) to C7 (Pr.905) (terminal
4). (Refer to
When both C42 (Pr.934) and C44 (Pr.935) ≠ "9999", calibrate the detector output and set point input by C42 (Pr.934) and C44 (Pr.935). (Refer
to page 433.)
Make calibration in the PU operation mode during an inverter stop.
• Calibrating set point input
(Example: To enter the set point on terminal 2)
1.
1. Apply the input (for example, 0 V) of set point setting 0% across terminals 2 and 5.
2.
Using C2 (Pr.902), enter the frequency (for example, 0 Hz) to be output by the inverter when the deviation is 0%.
3.
Using C3 (Pr.902), set the voltage value at 0%.
4.
Apply the input (for example, 5 V) of set point setting 100% across terminals 2 and 5.
5.
Using Pr.125, enter the frequency (for example, 60 Hz) to be output by the inverter when the deviation is 100%.
6.
Using C4 (Pr.903), set the voltage value at 100%.
430
16. (A) Application Parameters
16.4 PID control
Set the room temperature to 25°C.
Detector specifications
When 0°C 4mA and 50°C
on the assumption that 4mA is 0% and 20mA is 100%.
Make the following calibration  when the target setting input (0 to 5 V)
and detector output (4 to 20mA) must be calibrated.
• To set the set point to 50% using voltage input
The terminal 2 specification is 0 V for 0%, and 5 V for 100%. Thus, to set to 50%, input 2.5 V to the terminal 2.
• To set the set point to 50% using parameters
Set Pr.133 = "50". (If C42(Pr.934) and C44(Pr.935) ≠ "9999", set "25 (no % conversion)" directly in Pr.133.)
When performing operation, first set the proportional band (Pr. 129) to a slightly larger value, the integral time
(Pr. 130) to a slightly longer time, and the differential time (Pr. 134) to "9999" (no function), and while looking
at the system operation, decrease the proportional band (Pr. 129) and increase the integral time (Pr. 130).
For slow response system where a deadband exists, differential control (Pr. 134) should be turned ON and
increased slowly.
Yes
Parameter optimization
While the measured value is stable
throughout the operation status, the
proportional band (Pr. 129) may be
decreased, the integral time (Pr. 130)
decreased, and the differential time (Pr. 134)
may be increased.
page 358.)
20mA are used, the set point 25°C is 50%