Bürkert 8791, Руководство по эксплуатации

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Description of System
descripTiOn Of sysTeM 5.
general description 5.1.
The positioner Type 8791 is a digital, electro-pneumatic position controller for pneumatically actuated propor-
tional valves. The device incorporates the main function groups
- Position measuring system
- Electro-pneumatic control system
- Microprocessor electronics
The position measuring system measures the current positions of the proportional valve.
The microprocessor electronics continuously compare the current position (actual value) with a set-point position
value specified via the standard signal input and supplies the result to the position controller.
If there is a control difference, the electro-pneumatic control system corrects the actual position accordingly.
features 5.1.1.
version •
Positioner:
The position of the actuator is regulated according to the position set-point value. The position set-point value
is specified by an external standard signal or via field bus.
position measuring systems
•
- internal high resolution conductive potentiometer or
- external non-contact, non-wearing position measuring system (remote).
Microprocessor-controlled electronics •
for signal processing, control and valve control.
control module •
The unit is operated via 2 keys and 4 DIP switches.
3 LEDs indicate the status of the unit.
control system •
The control system consists of 2 solenoid valves and 4 diaphragm reinforcers. In single-acting actuators the
working connection 2 must be sealed with a threaded plug.
feedback (optional)
•
The feedback is implemented either via 2 proximity switches or via an 4 – 20 mA output.
The operator can change the initiators or limit positions via control lugs.
pneumatic interfaces •
Internal thread G1/4“
electrical interfaces •
Circular plug-in connector or cable gland
communications interface •
For configuration and parameterization
housing
•
Plastic-coated aluminium housing with hinged cover and captive screws.
english
Type 8791