Emerson FIELDVUEDVC2000 Instruction Manual download pdf

www.Fisher.com

Supplement to Fisherr FIELDVUEt DVC6000 or

DVC6200 Digital Valve Controller Instruction

Manuals

Implementation of Lock‐in‐Last Strategy

Many applications require a valve assembly to remain in the position it was prior to a specific control system failure

(lock‐in‐last position). Functionality and safety can be designed into valve assemblies with FIELDVUE digital valve

controllers by utilizing an array of accessories. The following paragraphs describe standard solutions for a number of

generic lock‐in‐last applications with DVC6000 or DVC6200 digital valve controllers.

Note

This instruction manual supplement is for use with HARTr communicating FIELDVUE DVC6000 or DVC6200 digital valve

controllers only.

Lock‐in‐Last on Loss of Supply Pressure

Once the supply pressure falls below a minimum value, the digital valve controller can no longer position a valve

assembly; the valve will start to go to the actuator “at rest” position. The locking device senses this change and

activates, preventing the remaining air from venting. The valve is “locked‐in” this new position.

Note

The locked‐in valve position depends on the exhausting speed of the actuator.

Assemblies with Single‐Acting Actuators

A Fisher 164A three‐way switching valve should be used for locking a single‐acting actuator in place on loss of supply

pressure. Figure 1 is a schematic representing proper assembly layout. In normal operation, the digital valve controller

output passes through the switching valve from port A to port B and on to the actuator.

Instruction Manual Supplement

D103261X012

DVC6000/DVC6200 Digital Valve Controllers

February 2011

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Summary of Contents

Page 1 - Instruction Manual Supplement

www.Fisher.comSupplement to Fisherr FIELDVUEt DVC6000 orDVC6200 Digital Valve Controller InstructionManualsImplementation of Lock‐in‐Last StrategyMany

Page 2

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20112Figure 1. Lock‐in‐Last on Loss of Supply Pressure for a

Page 3

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20113Connection of the digital valve controller output to a

Page 4

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20114Figure 3. Lock‐in‐Last Strategy for an Assembly with a

Page 5

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20115The solenoid valve in this solution does not require a

Page 6

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20116Figure 5. Lock‐in‐Last on Loss of Loop Current and/or S

Page 7 - Related Documents

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20117Figure 6. Lock‐in‐Last on Loss of Loop Current and/or S

Page 8

Instruction Manual SupplementD103261X012DVC6000/DVC6200 Digital Valve ControllersFebruary 20118Phoenix Threshold Switch Specifications(1)Switch Model