DVC6000f Series
March 2006
5-28
Tvl Press Control
(TB > Detailed Setup > Response Control > Tvl Press
Control)
Tvl/Press Select
Note
Travel / Pressure Select must be set to
Travel for double acting actuators.
Travel / Pressure Select (TVL_PRESS_SELECT
[41.1]) determines if the instrument is setup for
position or pressure control. Select Travel, Pressure,
Travel with Pressure Fallback/Auto recovery or Travel
with Pressure Fallback/Manual Recovery. If the travel
sensor fails, and Travel with Pressure Fallback/Auto
Recovery is selected, it will return to travel control
when the travel sensor starts working again. Travel
with Pressure Fallback/Manual recovery will stay in
pressure control until Travel Pressure Select is
changed to Travel or Travel with Pressure
Fallback/Auto recovery. It is not necessary to enable
the Travel Sensor Alert for Pressure Fallback to occur.
Tvl Cutoff Hi
Travel Cutoff Hi (FINAL_VALUE_CUTOFF_HI [15])
defines the high cutoff point for the travel in percent
(%) of pre-characterized setpoint. Above this cutoff,
the travel target is set to 123.0% of the ranged travel.
Travel Cutoff Hi is deactivated by setting it to 125.0%.
Tvl Cutoff Lo
Travel Cutoff Lo (FINAL_VALUE_CUTOFF_LO [16])
defines the low cutoff point for the travel in percent (%)
of pre-characterized setpoint. Below this cutoff, the
travel target is set to −23%. A Travel Cutoff Lo of 0.5%
is recommended to help ensure maximum shutoff seat
loading. Travel Cutoff Lo is deactivated by setting it to
−25.0%
Press Cutoff Hi
Pressure Cutoff Hi (PRESS_CUTOFF_HI [47.1])
defines the high cutoff point for the pressure in percent
(%) of pre-characterized setpoint. Above this cutoff,
the pressure target is set to 123.0%. A Pressure
Cutoff Hi of 99.5% is recommended to ensure valve
goes fully open. Pressure Cutoff Hi is deactivated by
setting it 125%.
Travel Target, %
Set Point, %
−25 0 125100
−25 0 125100
−25 0 125100
Input Characteristic Linear
Input Characteristic Equal Percentage
Input Characteristic Quick Opening
100
0
−25
125
Travel Target, %
100
0
−25
125
Travel Target, %
100
0
−25
125
A6535-1/IL
Figure 5-3. Travel Target Versus Ranged Set Point, for Various
Input Characteristics (Zero Control Signal Closed)
Set Point, %
Set Point, %
5