1、 Overview
The DFD operator is an intelligent product that integrates servo amplifiers, manual operators, and backup functions. It receives voltage, current, or resistance valve position given signals and outputs forward and reverse control signals. Suitable for use as a backup operator for DCS system loop regulation control output and intelligent regulator control output.
2、 Functional Features
1. When the operator is in automatic working mode, its function is similar to a servo amplifier, which adjusts and controls the error of the valve position feedback signal according to the valve position given signal to ensure that the actual valve position tracks the valve position given signal in a timely manner, achieving automatic control.
2. When the operator is in manual mode, its function is similar to that of an operator, which can directly operate the forward and reverse output signals through the ∧ and ∨ keys on the panel. That is, holding down the ∧ key outputs the forward signal, holding down the ∨ key outputs the reverse signal, and releasing the key does not output any control signal.
3. Valve position given input signals: standard signals such as 0-10mA, 4-20mA, 1-5V, 0-5V, etc.
4. Valve position feedback input signals: 0-10mA, 4-20mA, 1-5V, 0-5V, 0-10K Ω and other signals.
5. Valve position feedback output signals: 0-10mA, 4-20mA, 1-5V, 0-5V, and other signals.
6. Forward and reverse output signals: 40A/600V bidirectional thyristor control, capable of driving various specifications of electric regulating valves.
7. Remote manual control input: This signal only accepts dry contact signals and is usually connected to the fault status signals of the front-end DCS and intelligent regulator. Used to enable the operator to switch from automatic to manual mode in the event of a failure in the preceding stage, keeping the valve position unchanged to ensure that it does not lose control due to a failure in the preceding stage.
8. Hand automatic status output: relay formation
9. Dual screen display: The main screen displays the input signal for the given valve position, and the auxiliary screen displays the valve position opening.
10. The upper and lower limit states of the valve position opening can be set.
11. Display mode: 4-digit 0.8-inch or 0.56-inch LED display.
12. Current output: The load resistance is required to be less than 750 Ω.
13. Working environment: ambient temperature of 0-50 ℃, relative humidity below 85% RH.
14. Power supply: Conventional type: Linear power supply: 190-240VAC, 50HZ ± 2
Special type: Switching power supply: 90-260VAC50/60HZ/DC
DC power supply: DC24V ± 2V
15. Instrument structure:
Dimensions: 160 × 80 × 120mm 80 × 160 × 120mm 96 × 96 × 120mm
Hole size: 152×76mm 76×152mm 92×92mm
