Laurel Electronics LT: 4-20 mA & Serial Data Output Transmitter for 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 Output Transmitter
for Process Signals
Features
• Digital span adjust from 0 to ±99,999, zero adjust from -99,999 to +99,999
• 200 mV, 2V, 20V, 200V, 300V & 600V DC voltage input ranges
• 2, 20, 200 mA and 5A DC current input ranges
• All ranges 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
• Serial data output, isolated, Ethernet or RS232/RS485 (as ordered)
• Modbus RTU, Modbus ASCII or Laurel ASCII protocol
• 5V, 10V or 24V dc transducer excitation output, isolated
• Dual 120 mA solid state relays for alarm or control, isolated
• Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
Description
The Laureate process signal input transmitter provides six DC
voltage input ranges and four DC current input ranges for use
with a wide range of transducers whose output requires zero and
span adjustment. All ranges are factory calibrated and jumper
selectable. The two most sensitive voltage ranges, 200 mV and
2V, provide a high input impedance of 1 GΩ to minimize the load
on the voltage signal.
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.
The internal digital readings and analog output can be individu-
ally selected to be either unfiltered or filtered.
Digital signal filtering modes are selectable for stable readings
in electrically noisy environments. The internal digital readings
and analog output can be individually selected to be either
unfiltered or filtered.
• An unfiltered selection updates after each conversion for
fastest response, up to 60/sec, while integrating the input
signal over a full power cycle. Fast read rate 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. Another choice is
Auto, which provides an automatic time constant selection
based on the signal noise characteristics.
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 500 ohm (or lower) load for
10V compliance, or 10V into a 5K ohm (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).