Partial Stroke; Pst Enable - Fisher FIELDVUE DVC6200 Instruction Manual

DVC6200 Digital Valve Controller
Note
As a general rule, do not use less than
60% of the magnet assembly travel
range for full travel measurement.
Performance will decrease as the
assembly is increasingly subranged.
The linear magnet assemblies have a
valid travel range indicated by arrows
molded into the piece. This means that
the hall sensor (on the back of the
DVC6200 housing) has to remain
4
within this range throughout the entire
valve travel. See figure 2-4. The linear
magnet assemblies are symmetrical.
Either end may be up.

Partial Stroke (1-2-7)

(Instrument Level ODV)
Note
Partial Stroke is only available for
instrument level ODV.
Select Configure / Setup, Detailed Setup, and Partial
Stroke. Follow the prompts on the Field Communicator
display to configure the following partial stroke
parameters: PST Enable (Partial Stroke Test Enable),
and PST Vars View/Edit (View/Edit Partial Stroke Test
Variables).
D PST Enable
Yes or No. Enables or disables the Partial Stroke Test.
D PST Vars View/Edit
Follow the prompts on the Field Communicator display
to enter or view information for the following PST
Variables: Partial Stroke Tvl (Partial Stroke Travel),
Stroke Speed, Pause Time, PST Press Limit (Partial
Stroke Pressure Limit), PST Mode Enable (Partial
Stroke Enable), Pressure Set Point (Pressure Set
50
Point), and End Pt Contrl Enab (End Point Control
Enable).
Max Travel Movement—The default value for Max
Travel Movement is 10%. It may be set to a value
between 1 and 30% in 0.1% increments.
Note
The Max Travel Movement is the
percentage of total span that the valve
moves away from its operating state
towards its fail state during a Partial
Stroke Test.
Stroke Speed—The stroke speed can be set for
1%/second, 0.5%/second, 0.25%/second,
0.12%/second, or 0.06%/second. The default value for
Partial Stroke Speed is 0.25%/second.
Pause Time—The Setup Wizard sets the Partial
Stroke Pause Time to 5 seconds. This is the pause
time between the up and down strokes of the test. It
can be set for 5, 10, 15, 20 or 30 seconds.
PST Press Limit (single acting actuators)—During the
Setup Wizard, or Auto Travel Calibration, the Partial
Stroke Pressure Limit value will be set to a positive
value. For single acting actuators that vent from the
test starting point, the pressure limit will be a minimum
value. For those actuators that fill from the test starting
point, the pressure limit will be a maximum value. The
pressure signal used for this threshold depends on
relay type and is summarized below.
Relay Type
A or C
B
B Special App.
C Special App.
PST Diff Press— During the Setup Wizard or Auto
Travel Calibration, the PST Press Limit will be set to a
negative value for actuators where the Partial Stroke
Start Point is opposite of the Zero Power Condition
(e.g., Partial Stroke Start Point = Open and Zero
Power Condition = Closed) and to a positive valve for
actuators where the Partial Stroke Start Point is the
same as the Zero Power Condition.
To set the partial stroke pressure limit manually for
single acting actuators select min pressure. Select min
diff press for double acting actuators.
Pressure Signal
Port A − Port B
Port B − Port A
Port B
Port A
September 2010