Laureate™ V-to-F Process Receiver
(Integrating Totalizer Rate, analog square root, batch control, time based on rate)
- Square root readout from analog output of differential pressure flow transducers.
- 6-digit resolution.
- Isolated 5, 10, or 24 Vdc excitation output to power sensors.
- 25/s update rate.
- Green or red LED display.
- Optional dual relays, 4-20 mA & 0-10 V analog output, RS-232/485 I/O, and parallel BCD output.
- -1 mA, 4-20 mA, 0-10 V inputs, or special factory scaling.
- Field scalable for direct readout in engineering units.
- Selectable "count by" of 10 or 100 with rounding.
- Peak value display.
- NEMA 4X (IP-65) front panel, 1/8 DIN case.
- Certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark).
Extended Counter All capabilities of the Standard Counter, plus:
- Custom curve linearization.
- Batch control based on rate and total.
- Total based on rate and time.
- Display of process time based on rate input.
Rate with Square Root Extraction
A Laureate™ meter with the Standard counter main board and a voltage-to-frequency (V-to-F) signal conditioner board is able to accurately extract the square root of analog signals. The display is a full six digits. The three standard input ranges are 0-1 mA, 4-20 mA and 0-10 V. Special input ranges are available from the factory.
One application of the Standard V-to-F meter is to accurately display flow rate in engineering units, such as gallons per minute, from the 4-20 mA signal of a flow transducer with a linear or squared output.
Extended Counter Version
Batch Control with Linearized Total
The Laureate V-to-F meter with the Extended counter main board can also totalize the linearized flow rate derived from the analog rate signal, count up to a preset value, or down to zero from a preset value for batch control. The analog input may or may not require linearization. In addition to rate and total, the grand total of the batches or the number of batches can also be displayed by pressing a front panel key.
Use of the Extended V-to-F meter as an up or down-counting 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
One application of display of rate plus total is to read out kilowatts and kilowatt-hours based on 0-1 mA from a watt transducer.
Custom Curve Linearization
The relationship between the analog input and the value to be displayed can have a linear, square root, or custom curve relationship. For custom curve linearization, up to 240 data points can be input into a spreadsheet or text file by the user. The computer then calculates nonlinear segments, which are downloaded into the meter via RS-232. Custom-linearized rates can be totalized and be used for batch control.
Like the Extended analog DC panel meter, the Extended V-to-F meter can linearize and display analog inputs based on a custom curve unrelated to flow, for instance to read out the volume of an irregularly shaped tank based on level or pressure, or to linearize a nonlinear transducer.
Time Based on Rate
The Extended V-to-F 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 will be decreased.
Optional, plug-in analog output, dual-setpoint controller and RS-232/485 commu- nications or BCD output boards can upgrade the Laureate from a stand-alone monitor to system interface and control. In particular, the analog 4-20 mA or 0-10 V analog output will be linearized to the reading, which may be rate or total. All Laureate meters meet the NEMA 4X (IP-65) standard from the front for high pressure washdown when panel mounted.
High Resolution Display
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. In addition to a selectable gate time for rate measurement, an adaptive filter can reduce variations due to noise while rapidly responding to actual changes in signal level
Principles of V-to-F Operation
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 10-110 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 stored in nonvolatile memory in case of power loss
|Standard signal levels
||0-1 mA, 4-20 mA, 0-10 V
||5 Vdc ±5%, 100 mA max
|Other signal levels
||10 Vdc ±5%, 120 mA max
||24 Vdc ±5%, 50 mA max
||50 Vdc to meter ground
|85-264 Vac and 90-370 Vdc
||Gate time + 30 ms (max)
|DC or 49-440 Hz
||Selectable 10 ms to 199.99 s
||8-28 Vac and 9-37 Vdc
|Output & Display Updates
||Same as conversion time
||Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
||130 dB, DC to 60 Hz
||Differential or single-ended quadrature
||Max Pulse Rate
||250 kHz at x1, 125 kHz at x2, 62.5 kHz at x4
|x1, x2 or x4
||No error contributed by meter
||0°C to 55°C
||-40°C to 85°C
||95% at 40°C, non-condensing
||NEMA-4X (IP-65) when panel mounted
Flow from a Differential Pressure Transducer
An ideal application for the Standard Laureate V-to-F meter: readout of flow based on the 4-20 mA analog signal from a differential pressure transducer. Options include dual relays for alarm or control, isolated analog output to turn the meter into a transmitter, and RS-232/485 or BCD data communications.
Up- or Down-Counting Batch Controller
An ideal application for the Extended Laureate V-to-F meter: up- or down-counting batch controller. The dual-relay card is required. One relay is dedicated to batch control, the other relay is available to alarm the rate or total. The signal input can be linear or nonlinear. The display can be toggled between rate and total.
Linearizing Nonlinear Inputs
The Extended Laureate V-to-F meter can linearize analog signals for display and alarm using custom curve linearization with multiple nonlinear segments. As illustrated, tank level is measured by an ultrasound detector, which transmits a 4-20 mA signal. This signal is then converted to a highly accurate volume reading. The linearized rate readings can also be totalized.
Process Time from an Analog Rate Signal
A unique application of the Extended Laureate V-to-F meter: displaying process time based on the 4-20 mA or 0-10 V signal from a rate meter. In the above example, a tachometer transmits the speed of a conveyer belt through an oven. The meter displays baking time in the oven using the mathematical relationship time = distance / speed.
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001