Basic Examples of PID Control
Section
5-1
159
5-1-6 Time-proportional
Control
Follow the procedure below to perform time-proportional control where
contact output (ON/OFF) changes proportionately to the ON/OFF time ratio.
Function blocks used: Basic PID (Block Model 011)
Analog/Pulse Width Converter (Block Model 192)
Assign the MV of the PID function block to the Analog/Pulse Width Converter
block. The Analog/Pulse Width Converter block outputs the ON/OFF pulse
signal obtained by changing the ON and OFF times proportionally to MV.
PID
PV
MV
SSR
Analog/Pulse Width Converter
Time-proportional output
AI 4-point
Terminal
Block Model 586
PV
Basic PID
Block Model
011
A nalog input
MV
A nalog/Pulse
Width
Converter
Block Model
192
DO 16-point
Terminal
Block Model
514
Contact output
Time-
proportional
Contact
Distributor
Block Model
201