Instruction Manual

Instruction Manual Supplement

D103261X012

DVC6000/DVC6200 Digital Valve Controllers

February 2011

Figure 6. Lock‐in‐Last on Loss of Loop Current and/or Supply ressure for an Assembly with a Double‐Acting Actuator

(Fisher DVC6000 Depicted)

4‐20 mA

FISHER 377L

TRIP VALVE

24VDC POWER SUPPLY

PHOENIX

SWITCH

MCR‐2SP/UI

FISHER 64

REGULATOR

FISHER 252

AIR/GAS FILTER

AIR SUPPLY

SOLENOID VALVE

(ENERGIZED)

OUTPUT

SUPPLY

OUTPUT

DIGITAL

VALVE

CONTROLLER

NOTE:

THE ASCO 8320 SERIES SOLENOID VALVE OR EQUIVALENT IS APPROPRIATE FOR THIS ASSEMBLY.

Note

DVC6000 and DVC6200 digital valve controllers require approximately 0.5 seconds to initialize upon power up. During this time,

the digital valve controller cannot provide control. In the case where control of a previously locked valve is restored to a digital

valve controller prior to the completion of initialization, the valve will travel toward its fail‐safe position. A relay with an

engagement deadtime, such as the MCR‐2SP/UI from Phoenix Contact, can be used to delay the release of the locking system until

the digital valve controller has completely initialized. An engagement delay of 1.0 seconds will adequately minimize the dip in

travel.

Note

While the valve is in a locked state, the set point from the digital valve controller may change in response to changes in process

conditions. This change in set point may result in a process bump when control is restored to the digital valve controller.