Precision Digital Corporation Loop Leader+ PD4-6624, Instruction Manual

Page: 38 / 78

PD4-6624 & PD4-6628 Loop-Powered Flow Rate/Totalizers
Instruction Manual
38
Scaling Example
The 4-20 mA input can be scaled to the appropriate values for a given application. The 4 mA input (input 1) should
have a corresponding display value (display 1) which represents the low end of the process value range being
measured by the transmitter. Likewise, the 20 mA input (input 2) should have a display value (display 2) which
represents the high end of the process value range.
For example: If the meter is setup to accept a 4-20 mA input and display the flow of a pipe whose rate of flow is
between 0 and 100 gal/s, the transmitter would send a 4 mA signal when there is zero flow and a 20 mA signal when
there is maximum flow. The meter should be programmed to interpret these inputs on a display range of 0-100, so
that at 4 mA the meter will display 0 and at 20 mA the meter will display 100.
Processes which require a non-linear scale can be accommodated using the linear (
LINEAR
), exponent (
EXPONENT
),
and square root (
SQROOT
) functions available in the Advanced menu. See Input Signal Conditioning Functions
(
FUNCTION
) on page 54 .
A signal source is not needed to scale the meter; simply program the inputs and corresponding display values.
Setting the Display Features (
DISPLAY
)
The meter’s display functions may be programmed using the
Display menu. This menu consists of the following
submenus: Units , Decimal Point , Comma , Bargraph , Top , and Bottom .
Changing the Engineering Units (
UNITS
)
It is possible to change the display units without the need to re-scale the meter. When selecting a new unit from
within the
DISPLAY
menu (e.g. changing from gallons/sec. (
GAL/s
) to liters/sec. (
L/s
)), the meter will automatically
convert the display values to display the new unit. Enter the
UNITS
menu, select a new unit of measure from the list
of predefined units, and press the Enter button. If entering a custom unit (
CUSTM
), a custom conversion factor will
need to be entered.
Changing the Decimal Point (
DEC.PT
)
The decimal point may be set with up to seven decimal places or with no decimal point at all.
Pressing the Right-Arrow moves the decimal point one place to the right until no decimal point is displayed,
and then it moves to the left most position. Pressing the Up-Arrow moves the decimal point one place to the left.
The decimal point location is set independently for the rate, total and grand total.
DSPLY
UNITS
DSPLY
DEC.PT
DSPLY
COMMA
F2 F1 F2 F1
DSPLY
TOP
DSPLY
BOTTOM
DSPLY
BARGRAPH
F2 F1 F2 F1
SETUP
DISPLAY
MENU
ENTER
F3
F2 F1
DSPLY
DEC.PT
DEC.PT
222222.22
DEC.PT
1111111.1
Move Decimal
to the Right
DEC.PT
222222.22
DSPLY
COMMA
Accept
Decimal
Location
Move Decimal
to the Left
F1 F2
ENTER
F3
ENTER
F3
MENU