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Laureate - 6-Digit Analog Input Totalizer & Process Meter
Six-digit display of rate or total at the push of a front panel key. A Laureate with the Standard counter main board and a VF voltage-to-frequency signal conditioner board can be scaled to display rate or totalized rate to six digits for 0-1 mA, 4-20 mA or 0-10V analog process signals. Special input ranges are available from the factory. For example, the display can be scaled to show flow rate in gallons/minute or liters/sec, or to show volume in gallons or liters from the 0-10V output of a flow transducer. Or the display can be scaled to display power consumption in kilowatts or total utilized energy in kilowatt-hours based on the 0-1 mA output of a watt transducer. Square root extraction is selectable and can be applied to rate or total. This makes the VF Laureate ideal for use with differential pressure flow meters, which have a squared output. Totalized volume is based on linearized rate.
- Batch control based on linearized total. A Laureate VF meter with the Extended counter main board can totalize linearized flow from an analog rate signal, and also count up to a preset value, or count down to zero from a preset value for batch control. Operation as a batch controller requires the dual-relay output board option. One of the relays is dedicated to ON/OFF batch control. The other relay is available to slow down rate near the setpoint or to provide another alarm or control function based on rate or total.
- Custom Curve Linearization. For custom curve linearization, up to 180 data points can be input into a spreadsheet or text file by the user. The computer then calculates spline-fit segments, which are downloaded into the meter via RS232. The Extended VF meter can linearize and display analog inputs based on a custom curve, for instance to read out the volume of an irregularly shaped tank based on level or pressure, or to linearize a nonlinear transducer. Custom-linearized rates can also be totalized and be used for batch control.
- Time Based on Rate. The Extended VF meter can display a time inversely proportional to measured rate, such as the time that it will take a conveyor to traverse an oven. As the rate of the conveyor is increased, the displayed baking time is decreased.
The V-to-F signal conditioner board converts the full-scale 0-1 mA, 4-20 mA or 0-10 V analog signal to a frequency of 10 kHz to 110 kHz. This frequency is determined by measuring period over a selected gate time (from 10 ms to 200 s) and taking the inverse of period. Selecting a short gate time provides a much higher update rate than conventional counting-type frequency meters. At the lowest frequency of 10 kHz and the minimum gate time of 10 ms, the meter is capable of 25 updates per second. Scaling to rate in engineering units and totalizing are done mathematically. Totals are calculated as the product of rate and time in seconds regardless of the selected gate time. Totals are stored in nonvolatile memory in case of power loss.
The display of rate or total may be scaled to ±999,999. The two least-significant digits may be set to display zero with rounding or be active digits. Noise in rate readings can be reduced by selecting a longer gate time. In addition, an adaptive digital filter can reduce variations due to noise while rapidly responding to actual changes in signal level.
Hardware FeaturesOptional plug-in boards for communications and control include Ethernet and other serial communication boards, dual or quad relay boards, and single or dual isolated analog output boards. Laureates may be powered from 85-264 Vac or optionally from 12-32 Vac or 10-48 Vdc. The display is available with red or green LEDs. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can.