Pid Control Details; Proportional Operation (P Operation) - Mitsubishi MELSEC-Q series Programming Manual

1.4

PID Control Details

This section explains "proportional operation", "integral operation" and "derivative operation" performed for PID control using
the process control instructions.
1.4.1

Proportional operation (P operation)

This section explains the control method using proportional operation.
(1) Proportional operation is the action that compares the deviation (DV, difference between the set value and the process
value) to find the manipulated value (MV).
(2) The proportional term is given by:
MV = K • DV
P
K is a proportional gain constant.
P
(3) The proportional operation in the case of a step response with a constant deviation will be as follows.
(4) The manipulated value fluctuates between -10 and 110%.
As K increases, the manipulated value for the constant deviation also increases.
P
(5) Offset occurs in proportional operation.
14
DV
Time
K DV
P
Time