Liquid Controls SP2900 - Manual (Page 15)

COUNTER
The unit accumulates up to 8 digits of batch and grand total
count. In the setup mode choose “R0” (Reset to Zero ) for
adding operation or “SP” (Set to Preset) for subtracting
operation. While running display can be made to display an
8 digit grand total by pressing “ENT” while the unit is
running. Activating “CLR” while the grand total is flashing,
resets the grand total counter.
PRESETS
The unit has two independent presets. In the setup mode
the user selects whether the Counter, Rate Meter or Grand
Total counter activates either or both Preset A and Preset B
outputs. The preset numbers can be displayed or updated
at any time by pressing “A” (Preset A) or “B” (Preset B).
Enter the flashing preset number or press “CLR” and key in
a new number and “ENT” to enter it.
If the Total or Grand Total counter is set to control an
output, that output will activate for the time duration se-
lected under “RELAY” when the counter reaches the
selected preset number.
If the Rate is set to control and output, that output will be
activated when the rate equals or exceeds the preset rate
and drop out again when the rate goes below the preset
rate. Note that the preset for rate can be entered with
decimal when keying in the rate preset number.
RELAY - OUTPUT TIMING
Control output timing is selected by pressing D until the
RELAY mode is selected and entered. Any time duration
from .1 to 9.9 seconds or latch until reset (0.0 setting) may
be entered for the A and B outputs. Once the output has
been activated, the unit must be reset before another
output will occur.
SCALED OUTPUT/DATA LOST
The unit generates a pulse out for each factored count. An
NPN transistor output (Pin 2), capable of driving 100mA
from 30 VDC max., can drive external devices at rates of
10, 200, 2,000 or 20,000 counts per second as selected
through keypad menu. (Min. on/off times in milliseconds are
47.5, 2.0, 0.2 and 0.013 respectively). If the inputs scaled
by the K - Factor generate faster pulses than the output
speed selected, an internal buffer will store up to 9,999
counts before “DATALOST” flashes on the screen. This
indicates that the counts being totaled and the scaled
outputs may be incorrect. Note that all counts being totaled
and the scaled outputs may be incorrect. Note that all
counts stored in the internal buffer will be pulsed out at the
selected frequency even if the counter is reset.
RATE METER
Accurate to 5 1/2 digits (+ one display digit); the ratemeter
is autoranging and can be programmed by the K - Factor to
display almost any engineering unit of measurement. To
display the rate press the “C” (RATE/TOTAL) button while
the unit is displaying the batch. “R” is displayed on the left
side of the display to indicate that rate is being displayed.
The unit calculates the rate from the period between
pulses. The unit measures the average time between
pulses, divides this by the K - Factor and a reciprocal math
calculation to find the rate per second. As long as pulses
come in faster than 3 per second the unit will update each
second. The 2 to 24 second “WINDOW” time, selected at
set up, is the maximum time the unit will wait for sufficient
pulses to make an accurate calculation before it displays
zero.
1 to 6 “SIG FIG” (significant figures) can be selected in the
set up mode. The unit will normally display the number of
digits selected. The unit is auto ranging and will place the
decimal within these digits to display the true factored rate.
If the rate, scaled by the K - Factor, has more digits to the
left of the decimal point than the number of significant digits
selected, additional zeros will be added to fill in digit spaces
to the left of the decimal place. Eg. Factored rate is
123.456. A: “SIG FIG” set 4, display reads 123.4 B. “SIG
FIG” set 2, display reads 120. This allows the user to show
either the exact rate with the least significant digits chang-
ing with only a slight rate change or to create a more stable
display by showing zeros in the less significant digits.
NOTE: If the rate exceeds 7 digits, the display shows
“RFF...” indicating speed has been exceeded.
SETTING RATE K - FACTOR FOR PULSE
INPUT
K - Factor (rate per sec.) = pulses per unit (gallon, foot,
revolution)
K - Factor (rate per min.) = pulses per unit
60
K - Factor (rate per hr.) = pulses per unit
3600
The rate meter with a K - Factor of 1 displays the rate of
incoming pulses per second. To display the frequency or
rate per second simply key in the number of pulses per
gallon, revolution, foot or other unit of measurement. This
will usually be the same as the K - Factor used for the
count. If it is desirable to display the rate per minute, or
hour, divide the pulses per unit of measurement stated on
the sensor by 60 (rate per minute) or 3600 (rate per hour).
Example: A sensor generates 850 pulses per gallon and
you want to display gallons per hour. Set the counter K -
Factor at 850 to batch in gallons. Set the rate K - Factor at
0.2361111 (850 divided by 3,600). To convert to other units
of measurement calculate the number of pulses for the
desired unit of measure and use the formula above.
Example: Sensor give 850 pulses per gallon and you want
to batch in liters and display in liters per minute. (Example
uses conversion 1 gallon equals 3.78533 liters). Counter K-
Factor = 224.55109 (Sensor gives 224.55109 pulses per
liter - 850 divided by 3.78533). To find the rate per minute K
- Factor divide the count K - Factor for liter (224.55109) by
60 (seconds per minute) = 3.7425181.
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