IDEC MicroSmart Pentra - Manual (Page 24)

PID M ODULE M AIN F UNCTIONS
FC5A MicroSmart PID Module User’s Manual FC9Y-B1283 4-1
4: PID M
ODULE
M
AIN
F
UNCTIONS
This chapter describes the temperature control, fixed value control, auto-tuning (AT), program control,
heating/cooling control, difference input control, and cascade control of the PID module.
Temperature Control Using the PID Module
Temperature Control Configuration Example Using the PID Module
A. Sensor
Measures temperature of the control target. Thermocouple, resistance thermometer, voltage input,
or current input can be used as the sensor.
B. PID module
Receives the temperature measured by the sensor as the process variable (PV), and calculates the
output manipulated variable (MV) so that temperature difference (deviation) between the process
variable (PV) and the set point (SP) can be eliminated. The output manipulated variable (MV) is
outputted to the actuator as a control signal. Relay output, non-contact voltage output, or current
output can be used as the control signal.
C. Actuator
Receives a control signal from the PID module and turns on the load power supply to the heater.
Electromagnetic switches, SSR, or power controllers can be used as the actuator.
Optimal Temperature Control
The ideal temperature control, as shown in Figure 1, is to control the temperature to correspond with the
set point (SP) regardless of any disturbances. There should be no overshoot or response delay of time
until the temperature reaches the set point (SP).
Figure 1. Ideal Temperature Control Figure 2. Optimal Temperature Control
B. PID Module
A. Thermocouple
Control Target, such
as Electric Furnace
or Constant
Temperature Oven.
(電気炉、恒温槽など) Heater
C. Actuator
200V AC
Temperature
Set point (SP)
Time
Temperature
Set point (SP) B
Time
Set point (SP) A