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Operation as a process controller (s/hart, option), S/hart) – Burkert Type 8635 User Manual

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20 - 8635

S

YSTEM

D

ESCRIPTION

(S/HART)

If the SIDE Control

(S/HART) is operated as a process controller, the abovementioned position control

becomes a lower-ranking auxiliary control loop. The overall result is a cascade control system.

The process controller (as a main control loop) is implemented in the SIDE Control

(S/HART as a PID

controller. In this case the process setpoint (SP) is preset and compared with the actual value (PV) of
the process variable to be controlled, which is supplied by a sensor. Formation of the correcting variable
is done according to the description of the positioner. Z2 represents a disturbance acting on the
process.

Operation as a process controller (S/HART, option)

Characteristic of the process controller software (option)

Supplementary function

Effect

Positioner with supplementary functions

AUTOTUNE

Automatic adaptation of positioner to the control valve

in use.

Tight-closing function

Valve closes tight outside the control range. A value is
specified (in %) from which the actuator is completely
exhausted (at 0 %) or pressurized (at 100 %) .

Stroke limitation

Mech. valve piston movement only within a defined

stroke range.

Limitation of correction speed

Actuator takes a preset time to move from OPEN to

CLOSED or from CLOSED to OPEN.

Correction characteristic for
adaptation to the operating curve

Linearization of the process curve can be carried out.

Insensitivity range

The positioner responds only above a control difference
to be specified.

Direction of action of the controller

setpoint

Reverse of direction of action of the setpoint.

Direction of action of the actuator

Reverse of direction of action of the actuator.

Safety position

Valve moves to a defined safety position

Code protection

Blocking of the keypad or menu

Factory reset

Reset to factory settings