Hitachi SJ700D-004L Instruction Manual page 98

Chapter 4
(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
4-27
Explanation of Functions
Linear change
Large
A072
Small
Small
A073
Large
Large
A074
Small
PID target value
A006=01 A006=02
O + O2
(non-reversible) (reversible)
OI + O2 OI + O2
(non-reversible) (reversible)
O + O2
(non-reversible) (reversible)
OI + o2 OI + O2
(non-reversible) (reversible)
O2
(reversible)
A006=03
O + O2
O
OI
O + O2
O
OI