Bürkert 8792, Operating Instructions Manual

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14
Product description
Type 8792, 8793 REV.2
5.3 Variants
5.3.1 Type 8792, positioner
The position of the actuator is controlled according to the position set-point value. The position set-point value
is specified by an external standard signal (or via fieldbus).
5.3.2 Type 8793, process controller
Type 8793 also features a PID controller which, apart from actual position control, can also be used to
implement process control (e.g. level, pressure, flow rate, temperature) in the sense of a cascade control.
The process controller Type 8793 is operated with a 128 x 64 dot matrix graphics display and a keypad with
4 keys.
The process controller is linked to a control circuit. The set-point position of the valve is calculated from
the process set-point value and the process actual value via the control parameters (PID controller). The
process set-point value can be specified by an external signal.
5.3.3 Type 8793, remote variant
Depending on the connection variant type of the position sensor, Type 8793 functions as a
•
Process controller or
•
Positioner (position controller)
The following connection variants are available:
Function
Type 8793
Interface Position sensor Setting in the menu (ADD.FUNCTION)
Process
controller
digital (serial) Remote sensor Type 8798 POS.SENSOR → DIGITAL
For menu description see chapter
“16.1.21 POS.SENSOR” on page 118
Positioner
(position
controller)
analog
(4...20 mA) *
any high-resolution position
sensor
POS.SENSOR
→
ANALOG
For menu description see chapter
“16.1.21 POS.SENSOR” on page 118
Table 2: Connection variants Type 8793 with external position sensor
* If the external position sensor is connected to the process controller Type 8793 via the analog
interface, it can be operated only as a positioner (position controller).
The options for connection of an external position sensor are described in chapter “11.4 Remote
operation with external position sensor” on page 38.
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