4-20 mA Current Output Transmitter & Dual Pulse Input Totalizer

• Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
• Internal conversion of input to six-digit reading:
  • Digital span adjust from 0 to ±999,999
  • Digital zero adjust from -999,999 to +999,999
• Output accuracy: ±0.02% of span
• DIN rail mount housing only 22.5 mm wide
• Plug-in screw-clamp connectors
• Easy setup with PC-based Instrument Setup Software
• Universal AC power, 85-264 Vac
• Priced at only $235 (basic pulse input transmitter)

• Extended Main Board for Channel A total and Channel B rate simultaneously, Up/down counting on Channel A, using Channel B to control count direction, Counting on Channel A, using Channel B to inhibit counting, Arithmetic functions A+B, A-B, AxB, A/B, A/B-1 (draw).
• Low voltage power, 10-48 Vdc or 12-32 Vac.

The Laureate 4-20 mA transmitter for frequency, rate or period accepts two independently scalable input channels 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. The transmitter output can be selected as 4-20 mA, 0-20 mA or 0-10V, and is isolated to avoid ground loops. Applications include AC line frequency, RPM or speed from proximity switch inputs, and flow from turbine flow meter inputs.

• With a Standard Main Board, the transmitter output can be scaled to track frequency in Hz, rate (such as gallons per minute), or period (inverse of frequency). Square root extraction is standard.
• With an Extended Main Board, the transmitter output can track rate or totalized rate (such as gallons) whether the transducer output is linear, requires square root extraction, or requires custom curve linearization. The latter can be provided by a curvilinear spline fit with up to 180 data points. The transmitter can also count up to a preset total or down from a preset total to zero. Such applications typically make use of optional dual solid state relays, which are available as options. External reset of totals is via a special three-position screw terminal connector. The two input channels A & B can also be combined arithmetically to provide an analog transmitter output that tracks A+B (e.g., sum of two flows), A-B (e.g., difference of two flows), AxB (e.g., horsepower as product of force and RPM), A/B (ratio of two flow), and A/B-1 (draw or relative elongation of material between rollers).

The dual-channel signal conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from 12 mV to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions. A built-in 5V, 10V or 24V dc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.

Standard features of Laureate transmitters include:

• Analog transmitter output, 16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
• Serial communications, isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Laurel ASCII protocol.
• Dual solid state relays for control or alarm, isolated. Rated 120 mA at 130 Vac or 170 Vdc.
• Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
• Universal AC power supply for 85-264 Vac.