Siemens SIMATIC S7-1500T Function Manual

Using PID_Compact
4.2 PID_Compact V2
PID control
Function Manual, 03/2017, A5E35300227-AC
95
This example can be implemented with the following SCL program code:
"PID Compact 1"(Input := "Input1");
"PID Compact 2"(Input := "Input2");
IF "PID Compact 1".Output >= "PID Compact 2".Output THEN
"ActuatorInput" := "PID_Compact_1".Output_PER;
"PID_Compact_1".PIDCtrl.PIDInit := FALSE;
"PID_Compact_2".PIDCtrl.PIDInit := TRUE;
"PID_Compact_2".OverwriteInitialOutputValue := "PID_Compact_1".Output;
ELSE
"ActuatorInput" := "PID_Compact_2".Output_PER;
"PID_Compact_1".PIDCtrl.PIDInit := TRUE;
"PID_Compact_2".PIDCtrl.PIDInit := FALSE;
"PID_Compact_1".OverwriteInitialOutputValue := "PID_Compact_2".Output;
END IF;
4.2.4
Simulating PID_Compact V2 with PLCSIM
Note
Simulation with PLCSIM
The simulation of PID_Compact V2.x with PLCSIM for CPU S7
-1200 is not supported.
PID_Compact V2.x can only be simulated for CPU S7
-1500 with PLCSIM.
For the simulation with PLCSIM, the time
behavior of the simulated PLC is not exactly
identical to that of a "real" PLC. The actual cycle clock of a cyclic interrupt OB can have
larger fluctuations with a simulated PLC than with "real" PLCs.
In the standard configuration, PID_Compact determines the time between calls automatically
and monitors them for fluctuations.
For the simulation of PID_Compact with PLCSIM, for example, a sampling time error
(ErrorBits = DW#16#00000800) can therefore be detected.
This results in ongoing tuning being aborted.
The response in automatic mode depends on the value of the ActivateRecoverMode tag.
To prevent this from happening, you should configure PID_Compact for simulation with
PLCSIM as follows:
•
CycleTime.EnEstimation = FALSE
•
CycleTime.EnMonitoring = FALSE
•
CycleTime.Value: Assign the cycle clock of the calling cyclic interrupt OB in seconds to
this tag.

Siemens SIMATIC S7-1500T Specifications

General

Brand	Siemens
Model	SIMATIC S7-1500T
Category	Controller
Language	English