IDEC MicroSmart - Manual (Page 357)

« FC4A M ICRO S MART U SER ’ S M ANUAL » 21-1
21: PID I
NSTRUCTION
Introduction
The PID instruction implements a PID (proportional, integral, and derivative) algorithm with built-in auto tuning to deter-
mine PID parameters, such as proportional gain, integral time, derivative time, and control action automatically. The PID
instruction is primarily designed for use with an analog I/O module to read analog input data, and turns on and off a desig-
nated output to perform PID control in applications such as temperature control described in the application example on
page 21-14. In addition, when the output manipulated variable is converted, the PID instruction can also generate an ana-
log output using an analog I/O module.
Upgrade Information
Upgraded CPU modules of all-in-one 24-I/O types and slim types have an additional option for the integral start coeffi-
cient (S1+10) to execute an integral action within the proportional band. Applicable CPU modules and system program
versions are shown in the table below. For the procedure to confirm the system program version of the CPU module, see
page 29-1.
CPU Module
All-in-One Type Slim Type
FC4A-C10R2
FC4A-C10R2C FC4A-C16R2
FC4A-C16R2C FC4A-C24R2
FC4A-C24R2C FC4A-D20K3
FC4A-D20S3
FC4A-D20RK1
FC4A-D20RS1
FC4A-D40K3
FC4A-D40S3
System Program Version — — 202 or higher 202 or higher 201 or higher
• Special technical knowledge about the PID control is required to use the PID function of the
MicroSmart . Use of the PID function without understanding the PID control may cause the
MicroSmart to perform unexpected operation, resulting in disorder of the control system, dam-
age, or accidents.
• When using the PID instruction for feedback control, emergency stop and interlocking circuits
must be configured outside the MicroSmart . If such a circuit is configured inside the MicroSmart ,
failure of inputting the process variable may cause equipment damage or accidents.
Warning