Laurel Electronics LT: 4-20 mA & Serial Data Output Transmitter for DC Voltage or Current 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 Output Transmitter
for DC Voltage or Current Signals
Features
• ±0.2, ±2, ±20, ±200, ±300V and ±600V voltage input ranges
• ±2, ±20, ±200 mA and ±5A current input ranges
• All input ranges user selectable and factory calibrated
• 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
• 5V, 10V or 24V dc transducer excitation output, isolated
• 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
• Custom curve linearization and rate from successive readings (optional)
Description
Laureate DC input transmitters provides six voltage input
ranges and four current input ranges, all factory calibrated and
jumper selectable. The 200.00 mV and 2.0000 V ranges provide
a high input impedance of 1 GΩ to minimize the load on the
voltage signal. A 5.000A range measures the IR drop across a
built-in 10 mΩ current shunt. The transmitters can also easily be
scaled in software for use with external shunts.
Fast read rate at up to 50 or 60 conversions per second while
integrating the signal over a full power line cycle is provided by
Concurrent Slope (Pat 5,262,780) analog-to-digital conversion.
High read rate is ideal for peak or valley capture and for real-time
computer interface and control.
Digital signal filtering modes are selectable for stable readings
in electrically noisy environments.
• An unfiltered selection provides true peak and valley
readings and aids in control applications.
• A batch average filter selection averages each 16
conversions for an update every 1/4 sec.
• An adaptive moving average filter selection provides a
choice of 8 time constants from 80 ms to 9.6 s. When a
significant change in signal level occurs, the filter adapts by
briefly switching to the shortest time to follow the change, then
reverts back to its selected time constant. An Auto setting
selects the time constant selection based on signal noise.
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).
Standard features of Laureate LT 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 5KΩ (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. It also
allows use of Laurel Datalogging Software.
• Dual solid state relays, isolated. Available for local alarm or
control. 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 85-264 Vac power. Low-voltage 10-48 Vdc or
12-32 Vac power is optional.