Flow rate programming example 68 – Red Lion PCU User Manual

Page 76

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FLOW RATE PROGRAMMING EXAMPLE

A plastics manufacturer needs to maintain a constant flow rate on a feed

stock pipeline to insure their product stays within specification. A PCU is
installed to maintain the flow by controlling a proportional control valve.

The output of the flow meter is 0 to 10 VDC. The control valve is positioned

by an electric actuator that requires a 4 to 20 mA control signal.

The following is a list of the parameter values keyed-in to the controller.

Configure Input Parameters

tYPE

VOLT

Set input signal for voltage

dCPt

0.0

Scaled display to indicate in tenths

rnd

0.1

No rounding of the display

FLtr

1

Normal input signal filtering

dSP1

0.0

Display value for scaling point 1 is 0.0

INP1

0.00

Signal value for scaling point 1 is 0.00

dSP2

100.0

Display value for scaling point 2 is 100.0

INP2

10.00

Signal value for scaling point 2 is 10.00

SPLO

0.0

Limit min. setpoint value to 0.0 units

SPHI

110.0

Limit max. setpoint value to 110.0 units

SPrP

0.1

Setpoint ramp rate = 0.1 units/minute

INPt

trnF

Allow remote switching of auto/manual mode

Configure Output Parameters

CYCt

0

Main control output and indicator off

OPAC

rEV

Main control output is reverse acting

OPLO

0

Limit min. controller power to 0%

OPHI

100

Limit max. controller power to 100%

OPFL

0

Controller output power to 0 if input overdrive
signal is detected

OPdP

2.0

Output power dampening = 2.0

CHYS

0.1

Control hysteresis set for 0.1

tcod

0

Select fastest response

ANAS

OP

Linear DC output used for control

ANLO

0.0

Control valve provides full deflection for 4 to
20 mA signal range

ANHI

100.0

Andb

2.5

Impose 2.5% deadband on Linear DC output

ANut

2

Update output once every 2 seconds

Configure Alarm Parameters

Act1

A-HI

Set alarm #1 for absolute high acting

rSt1

LAtC

Alarm set for latching

Stb1

YES

Disable alarm during power-up

AL-1

90.0

Set alarm value for 90.0

Act2

A-LO

Set alarm #2 for absolute low acting

rSt2

LAtC

Alarm set for latching

Stb2

YES

Disable alarm during power-up

AL-2

20.0

Set alarm value for 20.0

AHYS

0.1

Alarm activation hysteresis set for 0.1

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