Simplicity on the Worksite
Solutions Guide for FAQs: E5
@
N
Using PID Control
3-1
Using PID Co
n
trol
Using PID Control
The procedure to use PID control is given step by step in this section.
The default setting is for reverse operation.
For heating control, select reverse operation.
For cooling control, select direct operation.
You can automatically or manually set the PID constants that are used for PID control.
Adjusting the PID Constants
The suitable values of the PID constants that are used for temperature control depend on the
characteristics of the controlled object.
There are three ways that you can use to set the PID constants. These are described
below.
⇒
Use autotuning (AT).
⇒
Set the PID constants
manually.
⇒
Use self-tuning (ST).
1
Select direct or reverse operation.
Step 1 Determining the Control Method
Set point
100%
0%
Temperature
Manipulated variable
Heating
Reverse Operation (Default)
The manipulated variable
increases if the temperature is
lower than the set point.
The manipulated variable
decreases if the temperature
is higher than the set point.
Set point
100%
0%
Temperature
Manipulated variable
Cooling
Direct Operation
The manipulated variable
increases if the temperature is
higher than the set point.
The manipulated variable
decreases if the temperature is
lower than the set point.
2
Adjust the PID constants.
If you can allow the temperature to vary while tuning the PID
constants and you need to calculate the optimum PID constants:
If you know the PID constants in advance:
If you cannot allow the temperature to vary and you need to
automatically estimate the PID constants when the set point is
changed:
With self-tuning, calculation of the PID constants is affected by
changes in the temperature, such as when a heater is turned
ON and OFF. The PID constants will be automatically
calculated and set. If there is an external source that causes
temperature changes (such as a heater turning OFF), use
autotuning or set the PID constants manually.
Summary of Contents for E5*N Series
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