13
Product description
Type 3280, 3285
The process controller is integrated in a control circuit. The position set-point value of the valve is calculated from
the process set-point value and the process actual value using the control parameters (PID controller). The process
set-point value can be specified by an external signal.
During the process control the position control mentioned above becomes the subordinate auxiliary control circuit;
this results in a cascade control. The process controller in the main control circuit has a PID function. The process
set-point value (SP) is specified as a set-point value and is compared with the actual value (PV) of the process
variable to be controlled. The position measuring system records the current position (POS) of the electromotive
linear actuator. This position actual value is compared by the position controller with the set-point value (CMD)
specified by the process controller. If there is a control difference (Xd1), the actual position (POS) and therefore
the valve opening are changed by the control variable (CTRL). Z2 represents a disturbance variable.
It is possible to communicate with the device digitally via CANopen* or büS**.
* CANopen - A CAN-based fieldbus (Controller Area Network) used in automation technology to link
devices.
** büS - A CANopen-based fieldbus with additional functions.
The positioner version also features some special functions (see chapter “8.3.1”), which can be set up using the
Bürkert-Communicator.
The operating instructions for the Bürkert-Communicator can be found at www.burkert.com
To Next Page
Loading...
