Fb59 "Tcont_S - Siemens SIMATIC Manual

Introduction
Description
Apart from the functions in the setpoint and process value branches, the FB
implements a complete PID temperature controller with a continuous and binary
manipulated variable output. To improve the control response with temperature
processes, the block includes a control zone and reduction of the P-action if there
is a setpoint step change.
The block can set the PI/PID parameters itself using the controller tuning function.
1.2

FB59 "TCONT_S"

FB59 "TCONT_S" is used to control technical temperature processes with binary
controller output signals for integrating actuators on the SIMATIC S7
programmable controllers. By setting parameters, subfunctions of the PI step
controller can be activated or deactivated and the controller adapted to the
process. These settings can be made simply in the parameter assignment user
interface. You start this within a project by double-clicking on the instance DB in the
SIMATIC Manager. You can open the electronic manual as follows:
Start > Simatic > Documentation > English > PID Temperature Control.
Application
The functionality is based on the PI control algorithm of the sampling controller.
This is supplemented by the functions for generating the binary output signal from
the analog actuating signal.
You can also use the controller in a cascade control as a secondary position
controller. You specify the actuator position via the setpoint input SP_INT. In this
case, you must set the process value input and the parameter TI (integral time) to
zero. An application might be, for example, temperature control with heating power
control using pulse-break activation and cooling control using a butterfly valve. To
close the valve completely, the manipulated variable (ER*GAIN) should be
negative.
Description
Apart from the functions in the process variable branch, FB 59 "TCONT_S"
implements a complete PI controller with binary manipulated value output and the
option of influencing the controller output signals manually. The step controller
operates without a position feedback signal.
1-4
PID Temperature Control
A5E00125039-02