35
Logix
®
520MD+ and 510+ Digital Positioners FCD LGENIM0105-15-AQ – 05/16
flowserve.com
8.3 Configuration Switch Settings
Before placing the unit in service, set the Configuration Switches to
the desired control options.
NOTE:
The Configuration Switch settings are activated only by
performing a Stroke calibration (pressing the “QUICK-CAL” but-
ton for 3 seconds). However, the Configuration Switch settings
may be edited from the DTM or Handheld at any time.
8.3.1 Air Action Switch
This must be set to match the configuration of the valve/actuator
mechanical tubing connection since the tubing determines the air
action of the system.
If Single Acting (Poppet) Relay
ATO - Increasing pressure from Port B (labeled “Y1”) causes the valve
to open.
ATC - Increasing pressure from Port B (labeled “Y1”) causes the valve
to close.
If Double Acting (Spool) Relay
ATO - Increasing pressure from Port A (labeled “Y1”) causes the valve
to open.
ATC - Increasing pressure from Port A (labeled “Y1”) causes the valve
to close.
8.3.2 Actuator Switch
This must be set to match the configuration of the actuator and is used
in some diagnostics.
Double - Select Double when both sides of the actuator are pressurized.
Single - Select Single when only one side of the actuator is pressurized.
8.3.3 Signal at Closed Switch
Normally this will be set to 4 mA for an Air-To-Open actuator configu-
ration, and 20 mA for Air-To-Close.
4 mA - Selecting 4 mA will make the valve close when the signal is
low (4 mA) and open when the signal is high (20 mA).
20 mA - Selecting 20 mA will make the valve close when the signal is
high (20 mA) and open when the signal is low (4 mA).
NOTE:
When using an Analog Output (AO) function of the
Multi-Function Card, the AO signal corresponds with the Signal
At Closed selection. If the valve closes with a 4 mA signal, the
AO will show a 4 mA signal at closed. If the valve closes with a
20 mA signal, the AO will show a 20 mA signal at closed.
8.3.4 Characterization Switch
The Characterization Switch allows a better match between the input
command and the actual fluid flow through the valve. This feature is
typically used with valves that have non-linear flow characteristics.
The positioner makes a correction by applying an adjustment to the
input command according to a characterization curve.
Linear - Select Linear if the actuator position should be directly
proportional to the command input signal. (For most rotary valves,
this setting gives an =% Cv characteristic due to their inherent =%
characteristics.)
Other - Select Other if one of the pre-set characterization curves or a
custom curve is desired. The default will be the Custom curve which
is populated with a standard 30:1 equal percent rangeability curve
which generally opens less than the input command. To select one of
the other curve options, use the LCD menu, a Handheld or the Valve-
Sight DTM. To modify the Custom curve, use the DTM. See section
10.3.6 Configuration (Characterization) for more information.
8.3.5 Auto Tune Switch
This switch controls whether the positioner will automatically tune
itself during the stroke calibration (Quick-Cal), or use preset tuning
parameters.
On - Selecting On enables an auto tune feature that will automatically
determine the positioner gain settings. The automatic tuning will be
based on response parameters measured during the latest Quick-Cal.
The valve response is a combination of these response parameters
and the current position of the Selectable GAIN Switch.
Off - Selecting Off forces the positioner to use one of the factory
preset tuning sets determined by the Selectable GAIN Switch. Settings
“B” through “J” are progressively higher predefined tuning sets.
Selecting “A” on the Selectable Gain Switch during a Quick-Cal allows
the user to use and preserve manually adjusted gains. See section
8.4 Stroke Calibration for more details.
NOTE:
The gain switch is live meaning that regardless of the
Auto Tune selection, the gain settings can be adjusted at any
time during operation by changing the selectable GAIN switch
position. See Figure 37.
