Modbus & Serial Output Transmitter & Dual Pulse Input Totalizer

Rate or total in same transmitter, square root extraction. DIN Rail mounted, digitally programmable.
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Serial ASCII or Modbus Transmitter, Dual Pulse Input Totalizer
Key Features
  • Down counting from preset to zero using negative scale factor
  • DIN rail mount housing only 22.5 mm wide
  • Plug-in screw-clamp connectors
  • Easy setup with PC-based Instrument Setup Software
  • 5V, 10V or 24V dc sensor excitation output, isolated
  • Dual solid state relays for alarm or control, isolated
Standard Frequency
  • Selectable Modbus or Laurel ASCII protocol
  • Two independent, scalable totals for Channels A & B
  • Pulse input rates to 1 MHz
  • 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 for differential pressure flow transducers
  • Output scalable to six transmitted digits:
    • Span adjust from 0 to ±999,999
    • Zero adjust from -999,999 to +999,999
  • 0-10V, 4-20 mA or 0-20 mA analog output, isolated
  • Universal AC power, 85-264 Vac
  • Priced at only $235 (basic totalizer transmitter)
Options
  • 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
Description

The Laureate Modbus & serial output, pulse input totalizer transmitter 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 pulse rates can be as high as 1 MHz.

  • With a Standard Main Board, the transmitter output can be scaled to engineering units, for example to transmit totalized flow in gallons from a flow meter output. 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), or 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.

LTM Series serial output transmitters send data via an isolated serial port, which is user configurable for RS232 or RS485 and full or half duplex operation. Three protocols are user selectable: Modbus RTU, Modbus ASCII, or Laurel ASCII. Modbus operation is fully compliant with Modbus Over Serial Line Specification V1.0 (2002). The Laurel ASCII protocol allows up to 31 Laureate devices to be addressed on the same RS485 data line. It is simpler than the Modbus protocol and is recommended when all devices are Laureates. It also allows use ofLaurel Datalogging Software.

Standard features of Laureate temperature 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.
  • Universal AC power supply for 85-264 Vac. Low voltage power of 10-48 Vdc or 12-32 Vac is optional.

Easy Transmitter programming is via Laurel's Instrument Setup Software, which runs on a PC under MS Windows. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL04).