Scale Conversion; Summary Of Parameters For Pid Control - Hitachi L100 300 User Manual

100
%
25
0
0 2V
0 4mA
0 20%
(a) A13 = 20%
A14 = 100%
A11 = 25%
A12 = 100%
As you can see from Fig 3-3, if you set parameters A11 and A12 other than "0", you should set the target
value inside the valid range of the vertical axis. Otherwise it is not possible to achieve stable performance
because there is no feedback value. That means the inverter will either output maximum frequency or
stop, or it will output lower limit frequency continuously if it is set.

(6) Scale Conversion

Using this function, you can set and display the target value and display the feedback value in the
actual units of the process variable. Set the parameters individually relative to 100% of feedback value.
With the factory default setting, the input and display value is based on 0 - 100%.
Example : In case of (a) in Fig.3-3, 20mA of feedback corresponds to 100% of PID internal calculation. For
instance, if actual flow at 20mA of feedback is 60 [m
100) in function mode A75. Then you can get the actual feedback value on the monitor mode
d04, and you can also set the target value by actual value of the control system.
L100/
Target
unit = [%] SJ100
Monitor F01 =
0 - 100[%]
Motor
(a) Factory setting
Fig. 3-4 Example of Scale Conversion
100
75
%
0
10V 0
0
20mA
0
100%
(b) A13 = 0%
A14 =
A11 = 0%
A12 =
Fig. 3-3 Setting Active Range : Example 2
Feedback
DC 4 -20mA
Monitor d01 =
0 - 100%
Fan
SJ100/L100 / PID / 9
100
75
%
25
5V 10V
10mA
20mA
50%
100%
50%
75%
3
/ min], you set the parameter to 0.6 (=60 /
L100/
Target
3
unit = [m /min] SJ100
Monitor F01 =
3
0 - 60[m /min]
(b) A75 = 0.6
0
0 2.5V 7.5V
20mA
0 5mA 15mA
0 25% 75% 100%
(c) A13 = 25%
A14 = 75%
A11 = 25%
A12 = 75%
Feedback
DC 4 -20mA
Monitor d01 =
3
0 - 60m /min
10V