Counters with Arithmetic Functions A+B, A-B, AxB, A/B, A/B-1 Applied to Channels A & B

Extended Counter

A/B, A/B-1 (draw), A+B, A-B, AxB arithmetic functions applied to Channels A & B.
Applicable to rate or total.
Frequencies from 0.005 Hz to 1 MHz.
Independent scaling for each channel.
Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
Update rate to 25/s.
Selectable "count by" of 10 or 100 with rounding.
Isolated 5, 10 or 24 Vdc excitation supply to power sensors.
Green or red 6-digit LED display.
NEMA 4X, 1/8 DIN case.
Dual relay option.
Analog output option.
Serial communication options.
Low voltage AC & DC power.
Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark), and RoHS.

Description

The A/B ratio and A/B-1 draw meters are selectable operating modes of the Laureate with Extended counter main board and FR dual-channel signal conditioner board.

Ratio can be used to compare flow rates in two channels, the RPM of rollers or gears, or the speed of moving machinery, such as conveyor belts. Ratio can also be applied to scaled totals to compare two batches to be mixed. In this application, one meter is used to monitor the ratio of flow rates, and a second meter to monitor the resulting batch totals.

Draw is obtained by subtracting 1 from ratio. Draw is often used to measure the elongation or shrinkage of material as it passes between rollers, or to monitor variation in the speed of rollers for tensioning.

Ratio and draw are similar, except that 1 is subtracted from ratio to obtain draw. The frequency of channels A and B is first measured and is then converted to rate in engineering units by multiplying it by the appropriate scale factor for that channel. Either rate can be displayed. The A/B ratio is then taken mathematically by the meter, and 1 is subtracted for draw. The result can be multiplied by a multiple or 10 from 0.0001 to 100000, and the decimal point can be set to display the result with the desired precision up to six digits.

Fast, High Resolution Measurement

The Laureate counter determines frequency by timing an integral number of periods over a programmable gate time. The inverse period approach allows greater accuracy and faster update times than conventional meters which count signal pulses over a specified time interval.

Channel A accepts pulses from 0.005 Hz to 1 MHz, while Channel B accepts pulses from 0.005 Hz to 250 kHz. At the minimum gate time of 10 ms, update rates can be up to 25/second. Such fast response is ideal for peak capture and for alarm and control applications. Variations in the displayed reading can be reduced by selecting a longer gate time. An adaptive filter can further reduce variations due to noise while rapidly responding to actual changes in the signal.

Universal Signal Conditioner

The Laureate dual-channel signal conditioner accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, low-level outputs from turbine flow meters down to 12 mV , and high-level AC line inputs up to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions.

A built-in isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.

Other Features & Options

A built-in isolated 5, 10, or 24 Vdc excitation supply can power the transducer and eliminate the need for an external power supply. Plug-in isolated analog output, dual-setpoint controller, and RS-232/485 communications, boards can upgrade the Laureate ratio meter from stand-alone monitor to system interface and control. In particular, the meter can provide an isolated 4-20 mA output signal scaled to the display. The 1/8 DIN case of Laureate meters and counters meets NEMA 4X (IP-65) standards from the front for high pressure wash-down when panel mounted.

Display
Readout Display Range Zero Adjust Span Adjust Indicators	6 LED digits, 7-segment, 14.2 mm (.56"), red or green LED -999999 to +999999, XXXXEX notation beyond 999999 -999999 to +999999 0 to 999999 Four LED lamps
Inputs
Types Signal Ground Channel A Frequency Channel B Frequency Minimum Signal Maximum Signal Noise Filter Contact Debounce	AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups Common ground for channels A & B 0.005 Hz to 1 MHz 0.005 Hz to 250 kHz Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V) 250 Vac 1 MHz, 30 kHz, 250 Hz (selectable) 0, 3, 50 ms (selectable)
Update Rate
Frequency Technique Conversion Time Gate Time Time Before Zero Out	Inverse period Gate time + 30 ms+ 0-2 signal periods Selectable 10 ms to 199.99 s Selectable 10 ms to 199.99 s
Accuracy
Time Base Span Tempco Long-term Drift	Crystal calibrated to ±2 ppm ±1 ppm/°C (typ) ±5 ppm/year
Power
Voltage, standard Voltage, optional Frequency Power Isolation	95-240 Vac ±10% or 90-300 Vdc (DC operation not UL approved) 12-30 Vac or 10-48 Vdc DC or 47-63 Hz 250V rms working, 2.3 kV rms per 1 min test
Excitation Output
5 Vdc 10 Vdc 24 Vdc Output Isolation	5 Vdc ±5%, 100 mA 10 Vdc ±5%, 120 mA 24 Vdc ±5%, 50 mA 50 Vdc to meter ground
Analog Output (optional)
Output levels Compliance Scaling Resolution Isolation	0-10V, 0-20 mA, 4-20 mA (jumper selectable) 2 mA at 10V (5 kOhm load), 12V at 20 mA (0-60 ohm load) Zero and full scale adjustable from -999999 to +999999 12 bits (0.025% of full scale) 250V rms working, 2.3 kV rms per 1 min test
Dual Contact Relay Outputs (optional)
Relay Type Load Rating Isolation	Form C 8A at 250 Vac or 24 Vdc 250V rms working, 2.3 kV rms per 1 min test
Dual Solid State Relay Outputs (optional)
Relay Type Load Rating Isolation	SPST, normally open, Form A 120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance 250V rms working, 2.3 kV rms per 1 min test
Serial Data I/O (optional)
Board Selections Protocols Data Rates Digital Addresses Isolation	RS232, RS485, Modbus RS485 Modbus RTU, Modbus ASCII, simpler Laurel ASCII 300 to 19200 bps 247 (Modbus), 31 (Laurel ASCII), 250V rms working, 2.3 kV rms per 1 min test
Environmental
Operating Temp. Storage Temp. Relative Humidity Protection	0°C to 60°C -40°C to 85°C 95% at 40°C, non-condensing NEMA-4X (IP-65) when panel mounted
Signal Connections

Controlling the Mixing Ratio of Two Fluids
	Displaying and alarming the input flow rate ratio of two fluids (gas or liquid) allows these to be mixed in a predetermined ratio in continuous processes. The sensing element is normally a turbine flowmeter, which outputs pulses at a frequency proportional to flow rate. The A/B ratio can also be displayed for totalized rate (or delivered volume).
Comparing Fluid Inflow & Outflow
	The ratio of the inflow and outflow rates of a tank is a measure of the relative filling or emptying rate. The same meter can also be programmed to display the net inflow or outflow rate in flow units, or to display totalized inflow our outflow in volume units. Any of these parameters can be alarmed using the dual relay board and be transmitted via 4-20 mA, RS-232 or RS-485.
Controlling Coating Thickness on a Film
	In this application, Channel A measures the rate at which a coating material is applied, as measured by a flow meter, while Channel B measures the speed of the film based on pulses from a proximity switch. Displaying and alarming the A/B ratio assures that an even thickness of coating material is applied as the speed of the film is varies.
Synchronizing Two Conveyor Lines
	The dual-channel Laureate counter can measure the speed of conveyor lines by using the output of proximity switches which sense gear teeth or spokes of rotating drive wheels. Displaying the speed ratio of two lines allows line speeds to be adjusted so that material arrives at work stations when needed.
Measuring Draw for Elongation
	Draw (Ch A / Ch B - 1) can be used to display the elongation of films compressed between rollers, the shrinkage films, and the RPM difference of rollers whose speed is varied to maintain tension. The six-digit resolution of the Laureate dual channel counter / rate meter is ideal for comparison of rates that are close to each other.

Ordering Guide
Laureate™ A/B Ratio & A/B-1 Draw Meters
Click on the radio buttons to build a model number with pricing.

Laureate™ Counters with Arithmetic Functions A+B, A-B, AxB, A/B, A/B-1 Applicable to dual channels A & B for rate or total.

Laureate™ Counters with Arithmetic
Functions A+B, A-B, AxB, A/B, A/B-1
Applicable to dual channels A & B for rate or total.