Laurel Electronics LT: 4-20 mA & Serial Data Output Transmitter for Thermocouple Types J, K, T, E, N, R, S - 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 Thermocouple Types J, K, T, E, N, R, S
Features
• Factory calibrated for thermocouple types J, K, T, E, N, R, S each in one range
• User selectable input span from entire thermocouple range down to 15.0°
• Output update rate to 60/sec
• 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
Description
The Laureate thermocouple transmitter provides a linearized,
highly accurate, stable and repeatable transmitter output for
thermocouple types J, K, T, E, N, R or S. The thermocouple type
and temperature range, specified in °C or °F, are user-selectable.
The temperature range can be as wide as the entire span of the
thermocouple type, or as narrow as 150 counts (such as 15.0°),
limited only by considerations of electrical noise and digital
filtering time constants.
Digital calibration of all thermocouple ranges is performed at
the factory, with calibration data stored in EEPROM on the signal
conditioner board. This allows signal conditioner boards and
ranges to be changed in the field with no need for recalibration.
Cold junction compensation automatically corrects for tempera-
ture variations at the thermocouple reference junction at the
transmitter. Open sensor indication is standard and may be set
up to indicate either upscale or downscale.
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.
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).