IDEC MICROSmart FC6A Series Ladder Programming Manual page 402

19: PID C I
ONTROL NSTRUCTION
■Control tab
This tab configures the control parameters for the PIDA instruction.
1.
2.
3.
4.
5.
6.
7.
8.
9.
1. Control Mode (S1+6)
Select PID (PID Control), P (Proportional Control), PI (PI Control) or PD (PD Control) according to the characteristics
of the target application.
For details about each control, see "PID Control" on page 19-23.
2. Control Action (S3+0)
• Select the control action from Direct Control Action or Reverse Control Action.
• Direct control action operates to increase the output manipulated variable when the process variable is higher than the set point.
Cooling equipment uses this operation. Reverse control action operates to increase the output manipulated variable when the process
variable is lower than the set point. Heating furnaces uses this operation. (S3+0) is read-only.
Output manipulated
variable
Set Point
100%
0%
Proportional Band
Direct control action
3. Set Point (S1+7)
The set point can be set between the minimum value and the maximum value of the process variable. The setting unit for the
set point is as follows.
When Analog Input thermocouple input or resistance thermometer input is set for the process variable, it can be set in units of
0.1°C/°F.
When Data Register or Analog Input voltage input, current input, thermistor, or resistance measurement is set for the
process variable, it can be set in units of 1.
19-12
Output manipulated
variable
100%
0%
Process variable
FC6A S MICROS L
ERIES MART
10.
Set Point
Process variable
Proportional Band
Reverse control action
P M
ADDER ROGRAMMING ANUAL
FC9Y-B1726