Hitachi L700 SERIES Instruction Manual page 89

(2) PID operation
1) P operation
The proportional (P) operation stands for the operation in which the change in operation quantity is in
proportion to the change in target value.
Target value
Operation quantity
2) I operation
The integral (I) operation stands for the operation in which the operation quantity increases linearly over
time.
Target value
Operation quantity
3) D operation
The derivative (D) operation stands for the operation in which the operation quantity changes in
proportion to the rate of change in the target value.
Target value
Operation quantity
The PI operation is a combination of the P operation 1) and I operation 2). The PD operation is a
combination of the P operation 1) and D operation 3). The PDI operation is a combination of the P
operation 1), I operation 2), and D operation 3).
(3) PV source setting
Select the terminal to be used for the feedback signal with the PV source setting function (A076).
The terminal to input the target value follows the frequency source setting (A001). The terminal selected by
the PV source setting (A076) is excluded.
If the control circuit terminal block ("01") has been specified for frequency source setting "A001", the
setting of AT selection (A005) is invalid.
The table below shows how the PID target value is selected according to the setting of "A006" when the
analog input is selected by the PV source setting and the control circuit terminal block ("01") is specified for
"A001".
PV source setting (A076)
00 (OI-L)
01 (O-L)
Operation targets include the
input to the OI terminal.
10 (operation Operation targets include the
result) input to the O terminal.
Operation targets are the inputs
to the OI and O terminals.
Change in steps
Large
A072
Small
Small
A073
Large
Large
A074
Small
A006=00
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Chapter 4 Explanation of Functions
Linear change
Large
A072
Small
Small
A073
Large
Large
A074
Small
PID target value
A006=01
O + O2
(non-reversible) (reversible)
OI + O2
(non-reversible) (reversible)
O + O2
(non-reversible) (reversible)
OI + o2
(non-reversible) (reversible)
O2
(reversible)
A006=02 A006=03
O + O2
O
OI + O2
OI
O + O2
O
OI + O2
OI