Laurel Electronics LTE: Ethernet & 4-20 mA Output Transmitter for Frequency, Rate or Period Input - Manual

LAUREL ELECTRONICS INC. , 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
Ethernet & 4-20 mA Output Transmitter
for Frequency, Rate or Period Input
Standard Features
• Ethernet Serial Data I/O, Modbus TCP or Laurel ASCII protocol
• 4-20 mA or 0-10V transmitter output, 16 bits, jumper selectable, isolated
• Dual 120 mA solid state relays for alarm or control, isolated
• 5V, 10V or 24V dc transducer excitation output, isolated
• Two independently field-scalable pulse input channels from 0.005 Hz 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
• DIN rail mount housing only 22.5 mm wide, detachable screw-clamp connectors
• Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
• Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
• Power over Ethernet (PoE) selectable with 10-48 Vdc supply
• Extended main board for simultaneous rate and total, custom curve linearization,
arithmetic functions A+B, A-B, AxB, A/B, A/B-1 (optional)
Description
The Laureate 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. Appli-
cations 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 in engineering units (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 cur-
vilinear 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. 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 out-
put 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 elon-
gation of material between rollers).
Exceptional accuracy and stability in frequency measurement
are achieved by taking the inverse of period 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 analog output is
generated by an ultra-linear 16-bit (65,536 step) digital-to-analog
converter (DAC).
Standard features of Laureate LTE transmitters include:
• Ethernet I/O, isolated. Supported protocols are Modbus
RTU and ASCII (tunneled via Modbus TCP) and Laurel ASCII.
The latter is simpler than the Modbus protocol and is recom-
mended when all devices are Laureates. Note that RS232 or
RS485 data I/O in lieu of Ethernet is provided by our LT Series
transmitters.
• 4-20 mA, 0-20 mA or 0-10V analog transmitter output,
isolated, jumper-selectable and user scalable. All selections
provide 16-bit (0.0015%) resolution of output span and 0.02%
output accuracy of a reading from -99,999 to +99,999 counts
that is also transmitted digitally. Output isolation from signal
and power grounds eliminates potential ground loop problems.
The supply can drive 20 mA into a 500 ohm (or lower) load for
10V compliance, or 10V into a 5K ohm (or higher) load for
2 mA compliance.
• Dual solid state relays, isolated. Available for local alarm
or control. Rated 120 mA at 130 Vac or 180 Vdc.
• Transducer excitation output, isolated. User selectable
5V@100 mA, 10V@120 mA or 24V@50 mA.
• Universal 85-264 Vac power. Low-voltage 10-48 Vdc or
12-32 Vac power is optional.
Discovery and configuration of Laureate Ethernet Nodes is
easily achieved with Laurel's Node Manager Software, and the
discovered transmitters can then be programmed using Laurel's
Instrument Setup Software. Both softwares run on a PC under
MS Windows and can be downloaded at no charge.