Sum, Difference, Ratio, Product for Rate or Total with 2 Input Channels
4-20 mA Current Transmitter DIN Rail mounted, digitally programmable.
Standard Main Board
- Isolated 4-20 mA or 0-10V transmitter outputs, selectable.
- Two independently field-scalable pulse input channels.
- Applicable arithmetic functions: A+B, A-B, AxB, A/B, A/B-1 (draw).
- Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac
- Square root extraction standard.
- DIN rail mount package only 22.5 mm thick.
- Easy setup using Laurel's PC-based Instrument Setup Software.
- Output resolution: 0.025% of span (12 bits).
- Internal conversion of Channel A & B inputs to six-digit readings:
- Digital span adjust from 0 to ±999,999.
- Digital zero adjust from -999,999 to +999,999.
- Frequencies from 0.005 Hz to 1 MHz.
- High output update rate.
- Isolated 5V, 10V or 15V dc excitation output to power transducers.
- Detachable screw clamp plug connectors.
- Optional dual solid state relays for alarm or control.
Laureate TM Series serial output, pulse input transmitters accept two independently scalable input channels A & B from a wide range of pulse sources, such as NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC voltages to 250 Vac. Input frequencies can range from 0.005 Hz to 1 MHz. With the Standard main board, the transmitter output can be programmed to track rate or total for both channels. With the Extended main board, as used in the transmitters being presented in this web page, the transmitter output can also be programmed to track the sum, difference, product, ratio, or draw of both channels: A+B, A-B, AxB, A/B, A/B-1. These arithmetic operations can be applied to scaled rates, scaled totals, square root of rates, totals after square root extraction, custom curve linearized rates, or totals after custom curve linearization.
Sum can be used to add two flows for total flow, or to add parts carried by two conveyor belts.
can be used to subtract outflow from inflow for net flow, or to subtract reject parts from total parts.
Product can be used to multiply two rates, for example to compute horsepower by multiplying torque by RPM.
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 transmitter is used to monitor the ratio of flow rates, and a second transmitter to monitor the resulting batch totals.
Draw is obtained by subtracting 1 from ratio. Draw is used to measure the elongation of material as it passes between rollers, or to monitor variation in the speed of rollers for tensioning.
Exceptional Accuracy and Stability
Laureate pulse input frequency and rate transmitters determine frequency by taking the inverse of period as measured with a calibrated quartz crystal time base. This results in extremely accurate and stable 6-digit internal readings (±999,999 counts), which are then processed in software. The output update rate is a programmed gate time + 30 ms + 0-2 signal periods. For a 60 Hz signal, the update rate would be 20 per second. Such fast update rates are ideal for alarm and control applications.
The output of the transmitters presented in this web page can be selected as 4-20 mA or 0-10V and is isolated to avoid ground loops. This output is generated by an ultra-linear 12-bit (4096 step) digital-to-analog convert (DAC), whose output span can be adjusted from 0 to ±999,999 input counts and zero can be adjusted from -999,999 to +999,999 input counts. The analog output has a rated accuracy of ±0.05% of output span.
The update rate of the analog output is a programmed gate time + 30 ms + 0-2 signal periods. For a 60 Hz signal, the update rate would be 20 per second. Such fast update rates are ideal for alarm and control applications.
Transmitter programming is via a three-terminal RS-232 port using Laurel's PC-based Instrument Setup Software. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL03).
The transmitters are housed in a DIN rail case that is only 22.5 mm (0.89") thick. Signal connections are via detachable screw clamp plug connectors.
||AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups.
||Common ground for channels A & B.
|Channel A Frequency
||0.005 Hz to 1 MHz.
|Channel B Frequency
||0.005 Hz to 250 kHz.
||Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V).
||1 MHz, 30 kHz, 250 Hz (selectable).
||0, 3, 50 ms (selectable).
|Time Base Accuracy
||Quartz crystal calibrated to ±2 ppm.
||A+B, A-B, AxB, A/B, A/B-1
|Transducer Excitation Output (standard)
|Jumper Selection 1
||10V @ 60 mA, isolated to 50V from signal ground
|Jumper Selection 2
||5V @ 50 mA, isolated to 50V from signal ground
|Jumper Selection 3
||15V @ 60 mA, non-isolated
|Dual Relay Output (optional)
||Two solid state relays, SPST, normally open, Form A
||120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance.
|Analog Output (optional)
||4-20 mA and 0-10 Vdc (selectable)
|Compliance, 4-20 mA
||10V ( 0-500 ohm load )
||2 mA ( 5 kOhm load )
||12 bits (4,096 steps)
||±0.05% of output span
|Output Update Rate
||Programmed gate time + 30 ms + 0-2 signal periods
||250V rms working, 2.3 kV rms per 1 minute test
||95-240V AC ±10% or 90-300V DC
|Low power option
||12-30V AC or 10-48V DC
||DC or 47-63 Hz
||250V rms working, 2.3 kV rms per 1 min test.
||120 x 101 x 22.5 mm
||35 mm rail per DIN EN 50022
||Detachable screw clamp plug connectors
||0°C to 70°C
||-40°C to 85°C
||95% at 40°C, non-condensing
Controlling the Mixing Ratio of Two Fluids
Transmitting 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 flow meter, which outputs pulses at a frequency proportional to flow rate. The A/B ratio can also be transmitted 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 transmitter can also be programmed to transmit the net inflow or outflow rate in flow units, or to transmit 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.
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. Transmitting 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 transmitter can measure the speed of conveyor lines by using the output of proximity switches which sense gear teeth or spokes of rotating drive wheels. Transmitting 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 indicate the elongation of films compressed between rollers, the shrinkage films, and the RPM difference of rollers whose speed is varied to maintain tension. The high resolution of Laureate dual channel transmitters is ideal for comparison of rates that are close to each other
Pinout Laureate Serial Output Transmitters
Pulse Input for Frequency, Rate or Period
(shown with optional analog output and dual relay output)
|Transmitter Powering a Single Sensor
|Transmitter Powering Two Sensors
||Transmitter with Active or Passive Sensors
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