Sample For Fb 58 "Tcont_Cp" (Continuous) - Siemens SIMATIC Manual

6.4

Sample for FB 58 "TCONT_CP" (Continuous)

The "continuous controller" sample contains a simple control loop with the
FB 58 "TCONT_CP" temperature controller and temperature process simulated
with PROC_C. The controller is set as a continuous controller. PROC_C
represents a 3rd order lag with an analog input.
The schematic below illustrates the control loop of the sample:
SP
PV
Program Structure
The controller and process block are called in OB35 with a cyclic interrupt time of
100 ms. When OB100 starts, the restart bits of the controller and process are set.
Process Block for Simulation of a Temperature Heating Zone
The block simulates a typical temperature process for heating that can occur as a
control zone in an extruder, an injection molding machine, an annealing machine or
as a separate furnace.
The schematic below is the block diagram of the controlled system PROC_C:
DISV GAIN
INV
+
PID Temperature Control
A5E00125039-02
LMN
TCONT_CP,
DB_TCONT_CP
TM_LAG1
Examples for the Temperature Controllers
INV
PROC_C,
DB_PROC_C
TM_LAG2
TM_LAG3
OUTV
AMB_TEM
+
OUTV
6-7