To calculate the process (input) values, multiply each process percent by
the full scale process input. For the above example this value would be 5
(volts) divided by 36 (ft.) multiplied by 24 (ft.) = 3.333 VDC. For example,
25.5% x 3.333 V = 0.849 V, 86.0% x 3.333 V = 2.866 V, etc.
The tables below show the scaling points which were calculated.
Display Process (Input)
(%FS, 0-1680.4 cu. ft.*)
(%FS, 0-3.333 VDC*)
0.00 0.0 0.00 0.000
1.25 20.0 25.50 0.849
6.49 104.3 41.00 1.366
15.33 246.5 54.00 1.800
27.70 455.5 65.50 2.183
43.66 702.3 76.10 2.536
63.19 1016.4 86.00 2.866
86.41 1389.9 95.40 3.179
100.00 1608.4 100.00 3.333
5.000 4019.2
* The values shown in this column are user calculated.
The previous chart shows the 9 scaling points (8 segments) for the cone
portion. The bottom line lists the final, 10th scaling point (9th segment), which
would cover the cylindrical (linear) portion of the hopper.
Listed below are the values to be entered in “Pro 2” to program this example.
“dECPNt” - “0.0” - Defines decimal point
“round ” - “0.1” - Defines rounding factor and dummy zeros
“SCALE” - “yes” - Continue with scaling program
“dSP 1” - “0.0” - Program first display point
“Inp 1” - “0.000” - Program first input voltage point
“dSP 2” - “20.0”
“Inp 2” - “0.849”
“SEGt” - “9” - Defines number of active linear segments
“SCALE” - “yes” - Continue with scaling
“dSP 3” - “104.3” - Program balance of scaling points
“INP 3” - “1.366”
“dSP 4” - “246.5”
“INP 4” - “1.800”
“dSP 5” - “455.5”
“INP 5” - “2.183”
“dSP 6” - “702.2”
“INP 6” - “2.536”
“dSP 7” - “1016.4”
“INP 7” - “2.866”
“dSP 8” - “1389.9”
“INP 8” - “3.179”
“dSP 9” - “1608.4”
“INP 9” - “3.333”
“DSP 10” - “4019.2”
“INP 10” - “5.000”
PEAK/VALLEY
The other features of the totalizer/linearizer option are peak and valley
detection and a re-zero (tare) function. The indicator will record the lowest
reading (valley) and the highest reading (peak), automatically, for later recall.
This information is valuable in monitoring the limits of the process over any
length of time since these values are stored at power-down to span over shifts,
days, etc. An external input can be programmed to reset or engage the unit into
a peak/valley reading indicator. Additionally, the peak and valley can be
viewed and reset from the front panel, if so programmed, and viewed and reset
from the serial communication option.
Note: The peak/valley measurement is not instantaneous and is based on a
nominal 2 second response time.
TARE
The re-zero (tare) function can also be controlled externally, by the front
panel or through serial communications. This feature can quickly compensate
for small shifts or drifts in the input signal or to re-zero every operation, such
as batching. If the display error is greater than 1% of span due to transducer
drift, it is recommended to rescale the unit with “Pro 1” or “Pro 2”, rather than
re-zero the input. The tare buffer can be cleared by “walking” through “Pro 2”,
using the “P” button or via serial communications.
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