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Transmitters, 4-20 mA & Modbus - Panel Meters - Counters - Timers - Ethernet - USB - RS485 - RS232

Ethernet & 4-20 mA Output Transmitter for Resistance in Ohms

Exceptional accuracy at high update rates. DIN Rail mounted, digitally programmable.

Ethernet transmitter

Features

  • Ethernet Serial Data I/O, Modbus TCP or Laurel ASCII protocol
  • 4-20 mA, 0-20 mA or 0-10V transmitter output, 16 bits, jumper selectable, isolated
  • Dual 120 mA solid state relays for alarm or control, isolated
  • Five jumper-selectable resistance ranges of 20.000 ohm to 200.00 kohm
  • Fixed factory-special resistance ranges of 2.0000 ohm or 2.0000 Mohm
  • 0.1 milliohm resolution on 2 ohm scale for contact resistance measurements
  • Custom curve linearization for changing resistance transducers
  • 2, 3 or 4-wire connection with lead resistance compensation
  • DIN rail mount housing only 22.5 mm wide, detachable screw-clamp connectors
  • Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
Description

The Laureate Resistance Transmitter is ideal for high-speed, high-accuracy resistance measurements in a production environment, such as contact resistance measurements. It is factory calibrated for five jumper selectable resistance ranges from 20.000 ohm to 200.00 kohm. Factory-special, fixed ranges of 2.0000 ohm or 2.0000 Mohm are also available. Accuracy is an exceptional ±0.01% of reading ± 2 counts. Resolution is one part in 20,000. In the 2 ohm range, resolution is 0.1 milliohm for contact resistance measurements.

Transmitter connections can be via 2, 3 or 4 wires. With 4-wire hookup, 2 wires are used for excitation and two separate wires are used to sense the voltage across the resistance to be measured, thereby eliminating any lead resistance effects. With 3-wire hookup, the transmitter senses the combined voltage drop across the RTD plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts the lead resistance if the excitation leads are the same.

Resistance input signal conditioner board

All resistance ranges are digitally calibrated at the factory, with calibration factors stored in EEPROM on the signal conditioner board. This allows ranges and signal conditioner boards to be changed in the field without recalibrating the transmitter. If desired, the transmitter can easily be calibrated using external standards plus scale and offset in software.

High read rates at up to 60 or 50 conversions per second while integrating the signal over a full power cycle are provided by Concurrent Slope (US Pat 5,262,780) analog-to-digital conversion. High read rates are ideal for high-throughput manufacturing processes. Peak and valley values are automatically captured and may be displayed via a front panel pushbutton command or a control signal at the rear connector, or be transmitted as serial data.

Custom curve linearization, available with the Extended version, makes this transmitter suitable for use with transducers whose output is a non-linear changing resistance. Linearization is provided by curvilinear spline fits, and the reading can be scaled in software for user-selected engineering units of measure.

Transmitter connections can be via 2, 3 or 4 wires. With 4-wire hookup, 2 wires are used for excitation and two separate wires are used to sense the voltage across the resistance to be measured, thereby eliminating any lead resistance effects. With 3-wire hookup, the transmitter senses the combined voltage drop across the RTD plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts the lead resistance if the excitation leads are the same.

Resistance input signal conditioner board

All resistance ranges are digitally calibrated at the factory, with calibration factors stored in EEPROM on the signal conditioner board. This allows ranges and signal conditioner boards to be changed in the field without recalibrating the transmitter. If desired, the transmitter can easily be calibrated using external standards plus scale and offset in software.

High read rates at up to 60 or 50 conversions per second while integrating the signal over a full power cycle are provided by Concurrent Slope (US Pat 5,262,780) analog-to-digital conversion. High read rates are ideal for high-throughput manufacturing processes. Peak and valley values are automatically captured and may be displayed via a front panel pushbutton command or a control signal at the rear connector, or be transmitted as serial data.

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 recommended when all devices are Laureates. Note that RS232 or RS485 data I/O in lieu of Ethernet is provided by 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.
  • 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 from this website at no charge.

Laureate Ethernet network by Laurel Electronics
Specifications
Range Resolution Accuracy Excitation Current ***
0-2.0000 Ω 0.1 mΩ ±0.01% of reading
± 2 counts
5 mA
0-20.000 Ω 1 mΩ 5 mA
0-200.00 Ω 10 mΩ 500 µA
0-2000.0 Ω 100 mΩ 50 µA
0-20000 Ω 1 Ω 5 µA
0-200.00 kΩ 10 Ω 500 nA
0-2.0000 MΩ 100 Ω 500 nA
* Jumper-selectable, precalibrated range.
** Factory-set fixed range.
*** The applied excitation current is sensed by the meter, which operates in a ratiometric mode and automatically compensates for any changes in excitation.
Signal Input
Input Resolution 16 bits (65,536 steps)
Input Accuracy ±0.01% of reading ± 2 counts
Update Rate, Max 50/sec at 50 Hz, 60/sec at 60 Hz
Analog Output (standard)
Output Levels 0-20 mA or 0-10 Vdc (selectable)
Compliance, 4-20 mA 10V (0-500Ω load )
Compliance, 0-10V 2 mA (5 kΩ load)
Output Resolution 16 bits (65,536 steps)
Output Accuracy 0.02% of output span plus conversion accuracy
Output Isolation 250V rms working, 2.3 kV rms per 1 minute test
Ethernet Data I/O (standard)
Type 10/100 Base-T Ethernet per IEEE 802.3
Data Rates 300, 600, 1200, 2400, 4800, 9600, 19200 baud
Output Isolation 250V rms working, 2.3 kV rms per 1 min test
Serial Protocols Modbus TCP, Modbus RTU, Modbus ASCII, Laurel ASCII
Modbus Compliance Modbus over Serial Line Specification V1.0 (2002)
Digital Addresses 247 for Modbus, 31 for Laurel ASCII
Dual Relay Output (standard)
Relay Type Two solid state relays, SPST, normally open, Form A
Load Rating 120 mA at 140 Vac or 180 Vdc
Power Input
Standard Power 85-264 Vac or 90-300 Vdc
Low Power Option 10-48 Vdc or 12-32 Vac
Power Frequency DC or 47-63 Hz
Power Isolation 250V rms working, 2.3 kV rms per 1 min test
Power Consumption 2W typical, 3W with max excitation output
Mechanical
Dimensions 129 x 104 x 22.5 mm case
Mounting 35 mm rail per DIN EN 50022
Electrical Connections Plug-in screw-clamp connectors
Environmental
Operating Temperature 0°C to 55°C
Storage Temperature -40°C to 85°C
Relative Humidity 95% at 40°C, non-condensing
Cooling Required Mount transmitters with ventilation holes at top and bottom. Leave 6 mm (1/4") between transmitters, or force air with a fan.
Pinout
Laureate™ Ethernet & 4-20 mA Output Transmitter for Resistance Input
LTE Ethernet transmitter pinout, analog input

Resistance Measurement with Excitation & Lead Compensation

Ohm transmitter hookup can be via 2, 3 or 4 wires to the J5 connector. The transmitter applies a fixed excitation current for each resistance range.
4-wire connection to resistance signal condidioner In 4-wire hookup, different pairs of leads are used to apply the excitation current and sense the voltage drop across the unknown resistance, so that the IR drop across the excitation leads is not a factor.
3-wire connection to resistance signal condidioner In 3-wire hookup, the transmitter senses the combined voltage drop across the unknown resistance plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts all lead resistance and compensates for ambient temperature changes if the two excitation leads are identical.
2-wire connection to resistance signal condidioner In 2-wire hookup, the transmitter senses the combined voltage drop across the unknown resistance and both lead wires. The voltage drop across the lead wires can be measured by shorting out the resistance during transmitter setup, and this voltage is then automatically subtracted from the combined total. However, changing resistance of the lead wires due to ambient temperature changes will not be compensated.
Applications

QA Application with Relays in Passband Mode

Deviation mode relay operation for QA testing of resistance A deviation limit (50 mΩ in this example) is set up around both sides of a setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and can be used for contact resistance testing in a production environment.
Ordering Guide
Laureate™ Ethernet & 4-20 mA Output Transmitter for Resistance Input
Click on the radio buttons to build a model number with pricing as shown below. Prices are in US dollars and do not include shipping or duty charges (export sales). Please see our explanations and limitations applicable to pricing and online orders. Prices shown are in US Dollars and are Laurel's manufacturer's suggested retail price (MSRP) in the USA. Orders are processed manually, not directly by our shopping cart system. You don't have to supply credit card information when placing an online order.

North American Orders. Laurel does not sell factory-direct in the USA or Canada. Online sales orders are filled through distribution. During the ordering process, you will have the chance to select an authorized Laurel distributor, or you can ask Laurel to refer you to a distributor. The distributor will then contact you to quote shipping, tax and duty (where applicable), and arrange for payment.

International Orders. If your ship-to address indicates that you are outside of the USA or Canada and Laurel has a distributor in your country, we will forward your order to that distributor for follow-up. If Laurel does not have a distributor in your country, we will email you an order acknowledgment and a pro forma invoice which states the product price, shipping charges, and wire transfer information, which includes a $25 bank wire transfer fee.

Questions about your order? Please email your distributor or sales@laurels.com
Configured model number LTE20R0
Configured price per model $320
Quantity 1
Extended price $320
Quantity
Transmitter
Type
LTE  4-20 mA & Ethernet output transmitter $295
LT  4-20 mA & RS232/RS485 output transmitter $235
Main Board 2  Standard Main Board $0
4  Extended Main Board $40
Note:  Extended allows custom curve linearization for scaled readings from a changing resistance.  
Power 0  Isolated 85-264 Vac or 90-300 Vdc $0
1  Isolated 10-48 Vdc or 12-32 Vac $30
Input
Range
R0  0-2 ohms (factory-special fixed range) $25
R1  0-20 ohms $0
R2  0-200 ohms $0
R3  0-2 kohms $0
R4  0-20 kohms $0
R5  0-200 kohms $0
R6  0-2 Mohms $25
Note:  The same signal conditioner board can be used for resistance and RTD temperature measurement.  
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