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produces a more stable reading as more cycles are averaged, but slows down
the update rate. At very low frequencies, the update rate of the meter is
controlled by the period. In totalizing mode, the gate is always open, but the
gate time setting still determines the update rate of the meter. See also
Time-
out
or
Time before zero output
.
Hysteresis, Band
A band in counts which controls relay action
symmetrically around a setpoint. The relay
closes (or opens) when the reading goes
above the setpoint plus one hysteresis limit,
and opens (or closes) when the reading
falls below the setpoint less one hysteresis
limit. A narrow hysteresis band can be used
to minimize relay chatter. A wide hysteresis
band can be used for control applications.
The hysteresis band will be equal to two
hysteresis limits.
Hysteresis, Split
Split hysteresis, where the setpoint is at the center of a symmetrical hysteresis
band, is an alternative to span hysteresis.
Item #
Also called Display Item. A numerical value in the meter available for display
under control of a front panel key or serial communications. For example, in the
A+B totalizer mode, the sum of A+B is Item #1, Total A is Item #2, and Total B
is Item #3. When the meter is reset, Item #1 is always displayed. To view
another Item, press the
RESET
key. For Item 1, the yellow View “V” LED is
unlit. For Item 2, the “V” LED is lit. For Item 3 the “V” LED flashes.
Menu mode
Meter programming mode used for input and range selection, setup, and confi-
guration. Entered into from the Run mode by pressing the MENU key. The
Menu mode can be locked out completely by a jumper on the power supply
board.
Meter Hold
A rear panel input which freezes the meter display and all meter outputs while
that input is tied to logic ground by a switch or is held at 0V (logic level true).
The meter will resume operation when the input is disconnected or is held at
+5V (logic level false).
Moving average filter
A digital filter mode which displays a weighting moving average of readings.
Eight moving average modes are selectable with the following equivalent RC
time constants: no filter, 0.1 sec, 0.2 sec, 0.4 sec, 0.8 sec, 1.6 sec, 3.2 sec, 6.4
sec.
Multiplier
A constant multiplier from 0.00001 to 100000 (in decade steps) that is com-
bined with a
scale factor
from 0.00000 to 9.99999 (fixed decimal point and
settable digits) to go from frequency in Hz to rate in engineering units such as
gallons per minute or from pulse counts to total in engineering units, such as
gallons. The combination of a 6-digit scale factor with a multiplier provides
Summary of Contents for 800 plus
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