Bias And Gain Calibration For Pid Displayed Values (Pr. 241, Pr. 759, C42(Pr. 934) To C45(Pr. 935)); Bias And Gain Calibration For Pid Displayed Values; (Pr. 241, Pr. 759, C42(Pr. 934) To C45(Pr. 935)) - Mitsubishi F700 Series Instruction Manual

PID control

4.20.2 Bias and gain calibration for PID displayed values

(Pr. 241, Pr. 759, C42(Pr. 934) to C45(Pr. 935))

 When both of C42(Pr. 934) and C44(Pr. 935)  "9999", bias/gain calibration is available for analog value of set
point, measured value, deviation value to perform PID control.
 "Bias" / "gain" function can adjust the relation between PID displayed coefficient and measured value input
signal. Examples of measured value input signals are 0 to 5VDC, 0 to 10VDC, or 4 to 20mADC, and they are
externally input.
Parameter
Name
Number
Analog input display
241
*1
unit switchover
PID unit selection
759
*1
C42
PID display bias
(934) coefficient
*2
C43
PID display bias
(934) analog value
*2
C44
PID display gain
coefficient
(935)
*2
C45
PID display gain
(935) analog value
*2
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 185)
*1 This parameter allows its setting to be changed during operation in any operation mode even if "0" (initial value) is set in Pr. 77 Parameter write
selection.
*2 The parameter number in parentheses is the one for use with the parameter unit (FR-PU04/FR-PU07(-01)).
(1) Calibration for PID displayed values (C42(Pr. 934) to C45(Pr. 935))
 Set PID display bias coefficient for terminal 4 input with C42(Pr. 934).
(Initial value is the coefficient for 4mA.)
 Set PID display gain coefficient for 20mA of the frequency command current (4 to 20mA) with C44(Pr. 935).
 When both of C42(Pr. 934) and C44(Pr. 935) 
treated as 0%, and C44(Pr. 935) as 100%.
 Three methods of bias/gain adjustment for PID displayed values are the following.
(a)Method to adjust any point by application of voltage (current) across the terminals 4 and 5.
(b)Method to adjust any point without application of voltage (current) across terminals 4 and 5.
(c)Method to adjust only the frequency without adjusting the voltage (current).
(For the detail of (a) to (c), refer to page 172.
Make adjustment by assuming C7 (Pr. 905) as C45 (Pr. 935), and Pr. 126 as C44 (Pr. 935).)
CAUTION
 When the voltage/current input specifications are changed with voltage/current input switch and using Pr. 73 and Pr. 267, be sure
to make calibration.
268
Initial Setting
Value Range
0
0
1
9999 0 to 43, 9999
0 to 500.00
9999
9999
20% 0 to 300.0%
0 to 500.00
9999
9999
100% 0 to 300.0%
"9999" and Pr.133 is set as the set point, the setting of C42(Pr. 934) is

100
Bias
C42(Pr.934)
0 20
0 4
Frequency setting signal
C43(Pr.934)
Displayed in %
Select the unit of analog input display.
Displayed in V/mA
This parameter changes unit of parameters and monitored
items that are related to PID control. Refer to page 316.
Set the coefficient on bias (minimum) side of terminal 4 input.
Displayed in %.
Set the converted % on bias (minimum) side current /voltage of
terminal 4 input.
Set the coefficient on gain (maximum) side of the terminal 4
input.
Displayed in %.
Set the converted % on gain (maximum) side of current/
voltage of terminal 4 input.
Initial value
Gain
C44(Pr.935)
100%
20mA
C45(Pr.935)
Description