Laurel Electronics LTM CTR SERIES PULSE, AC or PROCESS TOTALIZER INPUT, SERIAL DATA OUTPUT - Manual (Page 21)

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10. V-TO F CONVERTER SIGNAL CONDITIONER BOARD
This process receiver signal conditioner board converts 0-1 mA, 4-20 mA or 0-10 V analog
process signals to a frequency signal, which is then processed mathematically by the counter
main board to produce an internal reading of rate, total (time x rate), or 1/rate (time based on
rate). Square root extraction is selectable in software. With this capability, the transmitter can
output a 4-20 mA process signal which tracks flow rate or totalized flow from a differential
pressure flow transducer. The board needs to be configured via jumpers for the input signal
type. It is recognized by Instrument Setup software, which will bring up the applicable menu
items for the V-F Converter input option.
JUMPER SETTINGS
Input Range Jumper Position A1
0-10V
0-1 mA
4-20 mA
None
a
b
OPERATING MODES
• A Only (Rate A, Basic counter) accepts 0-1 mA, 4-20 mA or 0-10 V analog process signals
to calculate an internal rate reading, which is then converted to the analog output. Scaling
can be done by entering Scale and Offset, or using the Coordinates of 2 Points method.
Measurements are averaged over a Gate Time, which is programmable from 10 ms to
199.99 sec. Selecting a long Gate Time provides a slower display update rate, but superior
noise filtering. Moving average filtering is selectable for noise reduction. Square root
extraction is selectable for use with differential pressure flow transducers. Custom curve
linearization is available with the Extended counter.
•
A, A Total (Rate A, Total A, Basic Counter) allows rate to be determined as Item #1 and total
as Item #2. Rate can be scaled using Scale and Offset, or the Coordinates of 2 Points
method. Total can only be scaled using Scale and Offset. Total is calculated as the product of
rate and time in seconds. If square root extraction or custom curve linearization (available
with Extended counter) are selected, totalizing is of the linearized rate readings.
• 1/(A Rate) (Extended Counter) determines the inverse of rate. For example, this can be the
time it takes an item to traverse an oven at a measured rate. Like Rate, 1/Rate can be scaled
using Scale and Offset, or the Coordinates of 2 Points method. Square Root extraction can
be selected for rate. 1/Rate is not available with custom curves.