Precision Digital Corporation PD6800-0L1, Instruction Manual

Page: 14 / 24

PD6800-0L1 Explosion-Proof Loop-Powered Process Meter
Instruction Manual
14
Scaling the Meter (
SCaLe
)
The 4-20 mA input can be scaled to display the pro-
cess in engineering units. To scale the meter, enter
the value in milliamps (mA) for input 1, and then the
corresponding engineering units display value. Do the
same for input 2.
After entering the display 2 value, confirm the new
scale by pressing ENTER at the
Save
menu.
A signal source is not needed to scale the meter;
simply program the inputs and corresponding display
values.
For instructions on using multipoint scaling, see
Level
Input Multipoint Linearization
(
MULTIPT
) on page
19
.
Minimum Input Span
The minimum input span is the minimum difference
between input 1 and input 2 signals required to com-
plete the calibration or scaling of the meter. The min-
imum span is 0.10 mA.
Scale Error Message (
SPN ERR
)
If the minimum span is not maintained, the meter will
show a span error (
SPN ERR
) and revert to input 1,
allowing the appropriate input signals to be applied.
Note:
The Scale and Calibrate functions are exclusive
of each other. The meter uses the last function
programmed. Only one of these methods can be
employed at a time. The Scale and Calibrate
functions can use up to 32 points (default is 2). The
multi-point linearization should be enabled in the
Advanced Features menu under the Level Input
Multipoint Linearization
(
MULTIPT
)
menu selection,
prior to scaling and calibration of the meter, see
Advanced Features Menu
(
ADVANCE
)
on page 16.
Scaling the Tank Level Indicator
(
PERCENT
)
The display includes a 20-segment tank level
indicator. This menu sets full and empty values,
in engineering units, for the tank level indicator.
This value may differ from the 20 mA full-scale and
4 mA empty-scale values programmed in the
Scale
menu. This is ideal for level transmitters that output
less than 20 mA at the maximum height of the tank
or pit or more than 4 mA at the minimum height.
As an example, when using a level transmitter that
outputs 20 mA at 25 meters, the tank height indicator
may be set for a maximum of 10 meters. When the
meter reaches 10 meters on the display, the tank
height indicator will show full, even though the input
is not 20 mA.
Configuring the Display (
DISPLAY
)
The lower (
BOTTOM
) display may be configured to
display a custom tag (
TAG
), volume (
VOLUME
), volume
and tag (
VOL+TAG
), percent of full height (
PCT HT
),
percent of full height and tag (
PCT+TAG
), or be blank
(
OFF
).
A custom tag of up to seven alphanumeric characters
may be programmed for identification (e.g.
TANK 3
) or
for engineering units (e.g.
GALLONS
).
Percent full height shows the percent full of the tank
height level indicator programmed in the Scaling the
Tank Level Indicator (
PERCENT
) menu.
The tank level indicator (
GRAPH
) may also be turned
on or off from the display menu.
Note:
Volume is a separate, second scale of the input pro-
cess variable. This is configured in
Volume Display
Scaling (
VOLSCAL
) on page 18 .