Logix
®
520MD+ and 510+ Digital Positioners FCD LGENIM0105-15-AQ – 05/16
44
10.3.4 Calibration
.
Calibration
.
Stroke/Quick Calibration
.
Pressure Sensor Calibration
1
.
Friction Calibration
1
.
Triple Calibration
1
.
Command Input Calibration
.
Calibration Dates
1
1
Not available with 510+
The Calibration menu allows the user to calibrate the positioner’s
sensors. The positioner can accurately control with only a Quick-Cal.
Typically this is all that is needed. A friction calibration is recommended
if the positioner has been upgraded to Pro diagnostics. See section 8
STARTUP for more details.
a
CAUTION:
Performing a calibration may result in valve movement
and the inability to operate the valve until the calibration is com-
plete. Notify proper personnel that the valve may stroke, and make
sure the valve is properly isolated before proceeding.
Stroke/Quick Calibration starts an automatic calibration of the position
feedback sensor. The stroke calibration determines the closed (0%) and
open (100%) positions of the valve and gathers information about the
response of the valve (such as valve stroke time) in order to determine
the gains. The gains are then set automatically. After a stroke calibra-
tion, the positioner is ready to control.
See section 8.4 Stroke Calibration for more details.
Pressure Sensor Calibration starts an automatic calibration of the
pressure sensors. The pressure sensors are calibrated at the factory
and typically will not need calibration. Use this feature if new pressure
sensors are installed. If desired, configure the positioner to use the
most recent pressure calibration values after a factory reset. To do this,
write a 1 to variable 104 using the Edit Variables page of the ValveSight
DTM.
Friction Calibration starts an automatic calculation of total system
friction. This also determines the spring rate and other values critical to
the Pro diagnostic functions.
NOTE:
Friction forces may change quickly when a valve is first
placed into service.
Triple Calibration performs Stoke, Pressure and Friction calibrations in
one step.
Command Input Calibration is used to adjust the input range. Set the
lowest current (Set 0%) and the highest current (Set 100%) that will be
used. The default input range is 4 to 20 mA. The “Set 0%” value must
be lower than the “Set 100% value.
Split Range Example:
A split range is easily configured. For example, a 4 to 12 mA signal can
be set to correspond to a 0 to 100% stroke. When the display shows
“Set 0%”, set the command input current to 4 mA. (The display will
show a low Analog to Digital Count (ADC) that corresponds to 4 mA.)
Then press the
.
ACCEPT/QUICK-CAL button to set the value. Press the
.
Down button to move to “Set 100%”. Set the command input current
to 12 mA. (The display will show a high ADC to correspond to 12 mA.)
Again press the
.
ACCEPT/QUICK-CAL button to set the value. Select
the
,
Back Button to exit.
Signal At Closed = 20mA Example:
If the desired signal at closed is 20 mA, first set the Signal at Closed
DIP switch to 20 mA. Then perform a stroke calibration by pressing the
.
ACCEPT/QUICK-CAL button for more than 3 seconds. This registers
the DIP switch settings. Then, in the Command Input Calibration menu,
when the display shows “Set 0%” it is expecting the lowest current val-
ue. Set the input current to 4 mA. For “Set 100%”, it is looking for the
highest current value. Set the input current to 20 mA. After accepting
theses values, the positioner will interpret the 20 mA input as 0% valve
position and the 4 mA input as 100%.
Calibration Dates lists the most recent date of each calibration.
NOTE:
To calibrate the Analog Output, see section 13
MULTI-FUNCTION CARD.
10.3.5 Configuration (Positioner Tuning)
.
Configuration
.
Positioner Tuning
.
P-Gain Open
.
I-Gain Open
.
D-Gain Open
.
P-Gain Close
.
I-Gain Close
.
D-Gain Close
.
Open Stroke Time
.
Close Stroke Time
.
Minimum Open Time
.
Minimum Close Time
.
Gain Set
The Configuration – Positioner Tuning menu allows the user to man-
ually adjust individual tuning parameters. All tuning parameters are
automatically set to optimal values during Quick-Cal. Typically a Quick-
Cal is all that is needed for positioner tuning. See section 8 STARTUP
for more details.
a
CAUTION:
Adjusting the tuning parameters will affect the respon-
siveness of the valve and could cause rapid changes to the valve
position. Notify proper personnel that the valve may stroke, and
make sure the valve is properly isolated before proceeding.
P-Gain, I-Gain and D-Gain are the proportional, integral, and differential
elements of the feedback algorithm. These gains are different for the
opening and closing directions because typically responsiveness is
different in each direction.
