Laurel Electronics LT: 4-20 mA & Serial Data Transmitter-Totalizer for 0-1 mA, 4-20 mA or 0-10V Process Signals - Manual

LAUREL ELECTRONICS INC. , 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
4-20 mA & Serial Data Transmitter / Totalizer
for 0-1 mA, 4-20 mA or 0-10V Process Signals
Features
• 0-1 mA, 4-20 mA or 0-10V process signal input, isolated
• Converts signal input to a scaled rated or totalized rate
• Selectable square root for differential flow
• Output accuracy maintained for narrow or wide spans
• 4-20 mA or 0-10V transmitter output, jumper selectable, isolated
• Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
• RS232 or RS485 serial data output, half or full duplex, isolated
• Modbus RTU, Modbus ASCII or Laurel ASCII protocol
• Dual solid state relays for alarm or control, isolated
• Universal AC power, 85-264 Vac, or low voltage power, 10-48 Vdc or 12-32 Vac
• DIN rail mount case with detachable screw clamp connectors
Description
The Laureate process signal input transmitter and totalizer
accepts 0-1 mA, 4-20 mA or 0-10V signals from flow meters and
other transducers, such as watt meters, to track rate or totalized
rate.
• With a Standard Main Board, the transmitter output can track
rate (such as gallons per minute or watts) or totalized rate
(such as gallons or kilowatt hours) whether the transducer
output is linear or requires square root extraction (differential
pressure flow transducers).
• With an Extended Main Board, the transmitter can also
perform custom curve linearization (provided by a curvilinear
spline fit with up to 180 data points), display 1/ rate (such as
the time it takes a conveyor to pass through an oven), and
perform batch control for repetitive fill operations. Such
applications typically make use of optional dual solid state
relays, which are available as options. External reset of totals
is provided by a special connector.
The signal conditioner board of the transmitter converts the
full-scale 0-1 mA, 4-20 mA or 0-10 V analog signal to a frequency
of 10 kHz to 110 kHz. This frequency is determined by measuring
period over a selected gate time (from 10 ms to 200 s) and taking
the inverse of period. At the lowest frequency of 10 kHz and the
minimum gate time of 10 ms, the transmitter is capable of 25
updates per second. Scaling is done mathematically. Totals are
stored in nonvolatile memory in case of power loss.
Standard features of Laureate transmitters include:
• 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 500Ω (or lower) load for
10V compliance, or 10V into a 5 KΩ (or higher) load for 2 mA
compliance.
• Serial communications output, isolated. User selectable
RS232 or RS485, half or full duplex. 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.
• Dual solid state relays, isolated. Available for local alarm or
control. Rated 120 mA at 130 Vac or 170 Vdc.
• Universal 85-264 Vac power. Low-voltage 10-48 Vdc or
12-32 Vac power 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 our website at no charge. The
required transmitter-to-PC interface cable is available from Laurel
(P/N CBL04).