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.
Optional plug-in boards for communications and control include Ethernet, WiFi and serial communication boards, dual or quad relay boards, and an isolated analog output board. 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 be locked out for simplified usage and security. A built-in isolated 5, 10, or 24 Vdc excitation supply can power transducers and eliminate the need for an external power supply. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.
Display | |
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Readout | 6 LED digits, 7-segment, 14.2 mm (.56") |
Color | Red or green LED |
Range | -999999 to +999999 |
Indicators | Four LED lamps |
Inputs | |
Standard signal levels | 4-20 mA, 0-1 mA, 0-10V (jumper selectable) |
Input resistance | 50Ω at 4-20 mA, 1.00 kΩ at 0-1 mA, 1.01 MΩ at 0-10V |
Other signal levels | Consult factory |
Conversion | |
Frequency Technique | Inverse period |
Update Rate | Gate time + 30 ms (max) |
Gate Time | Selectable 10 ms to 199.99 s |
Accuracy | |
Span tempco | ±0.003% reading/°C |
Zero tempco | ±0.003% FS/°C |
Accuracy at 25°C | ±0.01% FS ± 1 count |
Power Supply Boards (one required) | |
Voltage, standard | 85-264 Vac or 90-300 Vdc |
Voltage, optional | 12-32 Vac or 10-48 Vdc |
Frequency | DC or 47-63 Hz |
Power consumption (typical, base meter) | 1.2W @ 120 Vac, 1.5W @ 240 Vac, 1.3W @ 10 Vdc, 1.4W @ 20 Vdc, 1.55W @ 30 Vdc, 1.8W @ 40 Vdc, 2.15W @ 48 Vdc |
Power Isolation | 250V rms working, 2.3 kV rms per 1 min test |
Excitation Output (standard) | |
5 Vdc | 5 Vdc ± 5%, 100 mA |
10 Vdc | 10 Vdc ± 5%, 120 mA |
24 Vdc | 24 Vdc ± 5%, 50 mA |
Output Isolation | 50 Vdc to meter ground |
Analog Output Boards (one optional) | |
Output levels | 4-20 mA, 0-20 mA, 0-10V, -10 to +10V (single-output option) |
4-20 mA, 0-20 mA, 0-10V (dual-output option) | |
Current compliance | 2 mA at 10V ( > 5 kΩ load) |
Voltage compliance | 12V at 20 mA (< 600 Ω load) |
Scaling | Zero and full scale adjustable from -99999 to +99999 |
Resolution | 16 bits (0.0015% of full scale) |
Isolation | 250V rms working, 2.3 kV rms per 1 min test |
(dual analog outputs share the same ground) | |
Relay Output Boards (one required for batch control) | |
Dual magnetic relays | 2 Form C, 8A at 250 Vac or 24 Vdc, 0.3A at 250 Vdc, resistive load |
Quad magnetic relays | 4 Form A (NO), 8A at 250 Vac or 24 Vdc, 0.3A at 250 Vdc, resistive load |
Dual solid state relays | 2 Form A (NO), 120 mA at 140 Vac or 180 Vdc, resistive load |
Quad solid state relays | 4 Form A (NO), 120 mA at 140 Vac or 180 Vdc, resistive load |
Relay commons | Isolated commons for dual relays or each pair of quad relays |
Relay isolation | 250V rms working, 2.3 kV rms per 1 minute test |
Relay latching modes | Latching or non-latching |
Relay active modes | Active on or off, active high or low |
Hysteresis modes | QA passband mode, split hysteresis, span hysteresis |
Communication Boards (one optional) | |
Board selections | RS232, RS485 with dual RJ11 connectors, RS485 with dual RJ45 connectors, USB, Ethernet, USB-to-RS485 gateway, Ethernet-to-RS485 gateway, WiFi with built-in antenna plus USB & RS485, WiFi with external antenna plus USB & RS485 |
Protocols | Laurel Custom ASCII (serial), Modbus RTU (serial), Modbus TCP (Ethernet or WiFi) |
Digital addresses | 247 (Modbus), 31 (Laurel ASCII), |
Isolation | 250V rms working, 2.3 kV rms per 1 min test |
Environmental | |
Operating temperature | 0°C to 55°C |
Storage temperature. | -40°C to 85°C |
Relative humidity | 95% at 40°C, non-condensing |
Protection | NEMA-4X (IP-65) when panel mounted |
Electrical Connections | |
Flow from a Differential Pressure Transducer | |
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An ideal application for the Standard Laureate VF 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 RS232/485 data communications.s | |
Up- or Down-Counting Batch Controller | |
An ideal application for the Extended Laureate VF 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. | |
Volume of an Irregularly-Shaped Tank | |
The Extended Laureate VF 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. Linearized readings can also be totalized. | |
Process Time from an Analog Rate Signal | |
A unique application of the Extended Laureate VF meter is displaying process time based on the 4-20 mA or 0-10 V signal from a rate meter. In this 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. |