The working principle of the intelligent valve positioner
The whole control circuit consists of two lines, 4 ~ 20 ma signal control, HART module send and receive superimposed on 4 ~ 20 ma signal of digital information, realize two-way digital communication with microprocessor, analog 4 ~ 20 ma signal to the microprocessor, comparing with the feedback from the valve position sensor, microprocessor control calculation according to the size of the deviation and direction (control), sent piezoelectric valve electric control instructions to make it open, closed, piezoelectric valve according to the control instruction corresponds to the width of pulse pneumatic amplifier output pressure increment, and the output of the pneumatic amplifier and feedback to the control circuit, comparing with the result of the microprocessor operation again (secondary control), through two levels of control output signal to the actuator, the change of air pressure in the actuator controls the valve stroke, when the control deviation is large, the piezoelectric valve a wide pulse signals, the positioner output a continuous signal, substantial changes to pressure actuated valve actuator signal rapid action: as close to the requirements of the valve position, the position of order and measured location difference decrescent, piezoelectric valve a smaller output pulse width of pulse signal, intermittent, small change to the actuator signal pressure, make the actuator is close to the action of a new command position gently, when the valve is reached the requirements of the position (into the dead zone), piezoelectric valve no pulse output, positioner output is zero, not in the position of the valve in a stable,
Smart valve positioner concise guide
Preparation:
1. According to the instructions for the PS2 and valve connection
2. Review and confirm the circuit and the connection of the road,
3. Electricity (4-20 ma current power supply)
4) prohibits voltage power supply
Initialization:
1. Confirm the Angle feedback (33 degrees and 90 degrees Celsius)
2. The use of adjustment of the wheel and feedback pole length adjustment PS2 zero and range (adjust wheel adjustment is zero, the feedback pole length adjustment fairly range)
3. Adjust lower limit range between 5% and 10%
4. Adjust the maximum range is less than 95%
5. Identify and maintain the valve position in 50%
6. Enter the parameter Settings and make sure the related parameters (parameter 1, 2, 3)
4 7. Enter the parameters, the start automatic initialization (such as manual initialization parameter to 5)
Ok today small knowledge here, regularly updated, welcome attention ah,