Logix
®
420 Digital Positioner FCD LGENIM0106-07-AQ – 10/15
18
9 POSITIONER FUNCTIONS
(No Display Required
)
The following features can be performed using the local interface. No
display is required for these features. Additional features are offered
with the use of a display, Handheld or DTM.
NOTE:
In order to prevent unintentional adjustments of the configura-
tion, tuning, or control of the valve, the Tamper Lock feature may be
used. This is set in the DTM and disables the buttons and menus except
for the ability to view the status of the positioner. When locked, the
positioner may be temporarily unlocked by entering a PIN. (An LCD is
required to enter the PIN.) Or, the positioner can be unlocked from the
DTM.
9.1 Live Manual Tuning (Adjusting the Gain)
Use the Selectable GAIN Switch to adjust the gain at any time during
operation. This adjustment takes effect immediately. For faster response
select settings above “E” (F-J). For more stable response, select
settings below “E” (B-D). See Figure 11: Selectable GAIN Switch on
page 17.
9.2 Local Control Of Valve Position
To manually adjust the position of the valve regardless of the input
command (analog or digital), press and hold the
▲
Up,
▼
Down and
◄
BACK buttons for about 3 seconds. The
▲
Up,
▼
down buttons
can then be used to position the valve. While in this mode the LED‘s will
flash a GRRY (green-red-red-yellow) sequence. To exit the local control
mode and return to normal operation, briefly press the
►
ACCEPT/
QUICK-CAL button.
1
CAUTION: When operating using local control of the valve, the
valve will not respond to external commands. Notify proper
personnel that the valve will not respond to remote command
changes, and make sure the valve is properly isolated.
9.3 Command Source Reset
Performing a command source reset will reset the command source
to analog if it has been inadvertently left in digital mode. This is done
by holding down both the
▲
Up and
▼
Down buttons, then briefly
pressing the
►
ACCCEPT/QUICK-CAL button.
9.4 Factory Reset
To perform a factory reset, hold
►
ACCEPT/QUICK-CAL button while
applying power. All of the internal variables including calibration will
be reset to factory defaults. The positioner must be re-calibrated after
a factory reset. Tag names and other user configured limits, alarm
settings, and valve information will also be lost and need to be restored.
A factory reset will always reset the command source to analog
4-20 mA.
1
CAUTION: Performing a factory reset may result in the inability
to operate the valve until reconfigured properly. Notify proper
personnel that the valve may stroke, and make sure the valve is
properly isolated.
