User Manual

PID is easy
8.2 PID_Compact instruction
Easy Book
Manual, 03/2014, A5E02486774-AF
173
8.2
PID_Compact instruction
The PID_Compact instruction provides a universal PID controller with integrated self-tuning
for automatic and manual mode.
Table 8- 3 PID_Compact instruction
LAD / FBD
SCL
Description
"PID_Compact_1"(
Setpoint:=_real_in_,
Input:=_real_in_,
Input_PER:=_word_in_,
Disturbance:=_real_in_,
ManualEnable:=_bool_in_,
ManualValue:=_real_in_,
ErrorAck:=_bool_in_,
Reset:=_bool_in_,
ModeActivate:=_bool_in_,
Mode:=_int_in_,
ScaledInput=>_real_out_,
Output=>_real_out_,
Output_PER=>_word_out_,
Output_PWM=>_bool_out_,
SetpointLimit_H=>_bool_out_,
SetpointLimit_L=>_bool_out_,
InputWarning_H=>_bool_out_,
InputWarning_L=>_bool_out_,
State=>_int_out_,
Error=>_bool_out_,
ErrorBits=>_dword_out_);
PID_Compact provides a PID controller with
self-tuning for automatic and manual mode.
PID_Compact is a PID T1 controller with
anti-windup and weighting of the P- and D-
component.
1
STEP 7 automatically creates the technology object and instance DB when you insert the instruction. The instance DB
contains the parameters of the technology object.
2
In the SCL example, "PID_Compact_1" is the name of the instance DB.
Table 8- 4 Data types for the parameters
Parameter and type
Data type
Description
Setpoint
IN
Real
Setpoint of the PID controller in automatic mode. (Default value: 0.0)
Input IN Real A tag of the user program is used as the source of the process value.
(Default value: 0.0)
If you are using the Input parameter, you must set
Config.InputPerOn = FALSE.
Input_PER IN Word An Analog input is used as the source of the process value. (Default
value: W#16#0)
If you are using the Input_PER parameter, you must set
Config.InputPerOn = TRUE.
Disturbance
IN
Real
Disturbance variable or pre-control value