LT DIN Rail Analog Transmitter with Serial Data Communication and Analog outputs for DC Voltage and Current Input Signal

LT DIN Rail Analog Transmitter with Serial Data Communication and Analog outputs for DC Voltage and Current Input Signal

Price: $334.00
  • P/NLT20DCV1
- +
DC Voltage input signal

Features

  • ±0.2, ±2, ±20, ±200, ±300V and ±600V voltage input ranges
  • ±2, ±20, ±200 mA and ±5A current input ranges
  • Accuracy ±0.01%  of reading ± 2 counts 
  • All input ranges are user selectable and factory calibrated
  • Up to 60 conversions per second, Ideal for peak or valley capture
  • 4-20 mA, 0-20 mA, 0-10V or -10V to +10V transmitter output, (isolated)
  • Analog output resolution 0.0015%  of span, accuracy ±0.02%  of span
  • RS232 or RS485 serial data, Modbus or Laurel ASCII protocol (isolated)
  • Dual 120 mA solid state relays for alarm or control (isolated)
  • 5V, 10V, 12V, or 24V dc transducer excitation output (isolated)
  • Power 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac (isolated)
  • DIN rail mount housing, 22.5 mm wide, detachable screw-clamp connectors
  • Operating temperature from -40°C to 70°C (-40°F to 158°F)
    Optional - Extended allows up to 180 data points for custom curve linearization and a rate derived from consecutive readings.

The Laureate™ LT Series DIN rail analog transmitter with serial data communication and analog outputs for versatile connectivity.

The digitally programmable transmitter features two relays for alarm or control. The series offers exceptional accuracy of 0.01% of reading ± 2 counts, with high read rates at up to 60 or 50 conversions per second. The LT Series transmitters offer the same high performance, signal conditioning, and programmable features as Laureate digital panel meters, counters, and timers.

The Laureate 4-20 mA, 0-20 mA, 0-10V or -10V to +10V and RS232/RS485 output transmitter for DC voltage and current inputs:

  • DC voltmeter operation (selected by jumpers) provides and six full-scale DC voltage ranges from ±200.00 mV with 10 mV resolution to ±600.0V with 100 mV resolution. The 200.00 mV and 2.0000V ranges provide a high input impedance of 1 Gohm to minimize the load on the voltage signal.
  • DC ammeter operation (selected by jumpers) provides four full-scale DC current ranges from ±2.0000 mA with 0.1 mA resolution to ±5.000 A with 1 mA resolution. The 5.000 A range measures the IR drop across a built-in 10 milliohm current shunt.

All signal conditioner board ranges are factory-calibrated, with calibration factors for each range securely stored in an onboard EEPROM. These factors can be scaled via software to accommodate external shunts, enabling field replacement of signal conditioner boards without necessitating recalibration of the associated transmitter. For optimal accuracy, factory recalibration is recommended annually. All Laurel Electronics instruments undergo factory calibration using the industry-leading Fluke calibrators, which are recalibrated yearly and certified traceable to national standards, ensuring the highest level of precision and reliability.

The optional extended Laureate computer board enhances Laureate transmitter by displaying rates derived from successive readings and enabling highly accurate custom curve linearization. For example, it can calculate liquid volume or flow rate in a horizontal cylindrical tank using levels from a 4-20 mA transmitter. Setup is straightforward: users input up to 180 data points into a spreadsheet or text file, and the computer calculates spline-fit segments, which are then downloaded to the transmitter for precise operation.

Laureate Transmitters are easily programmed with Laurel’s free Instrument Setup Software, downloadable from our website and compatible with Windows PCs, requiring a data interface board for setup.

High read rate of up to 50 or 60 conversions per second, the Laureate™ LT Series transmitter uses Concurrent Slope (US Pat. 5,262,780) analog-to-digital conversion to integrate signals over a full power line cycle (50 Hz or 60 Hz). This read rate enables peak and valley capture, real-time computer interfacing, and control applications. Peak and valley values are automatically captured and can be viewed using Laurel’s free Instrument Setup Software (compatible with Windows PCs) or transmitted as serial data.

Standard Hardware Features of Laureate LT Transmitters Include:

  • Serial communications output, (isolated), RS232 or RS485 (half or full duplex), jumper selectable. 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 is simpler than the Modbus protocol and is recommended when all devices are Laureates.
  • 4-20 mA, 0-10V or -10V to +10V analog transmitter output, (isolated), jumper-selectable and user scalable. All selections provide 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. Note that Ethernet data I/O is provided by Laurel's LTE series transmitters.
  • Dual solid state relays, (isolated), for alarm or control. Rated 120 mA at 130 Vac or 180 Vdc.
  • Selectable transducer excitation output, (isolated), user selectable 5V@100 mA, 10V@120 mA, 12V@100mA, or 24V@50 mA.
  • Power 85-264 Vac, (isolated), low-voltage 10-48 Vdc or 12-32 Vac power is optional.

Digital signal filtering modes can be selected to ensure 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.
  • An adaptive moving average filter selection provides a choice of 8 time constants from 80 ms to 9.6 seconds. 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.

Two tare functions: auto-tare and manual tare. In auto-tare, an input line is grounded by an external pushbutton. This causes the current weight, which is normally the empty weight of the container to be stored in memory as an offset. In manual tare, the tare value can be entered manually via a control input pushbutton or using Laurel's free Instrument Setup Software.

Peak and valley values are automatically captured. These may be displayed via Laurel's free Instrument Setup Software,  which runs on a PC under MS Windows or can be transmitted as serial data.

Two control inputs (CMOS/TTL levels, logic 0 = tied to digital ground, logic 1 = open) or dry contacts that can be set to control / activate 14 transmitter commands.

An (isolated) 5, 10, 12, or 24 Vdc excitation output is standard to power transducers or two-wire transmitters. Ratiometric operation, which automatically compensates for changes in the applied excitation, is jumper selectable for applications, such as bridges, where the signal to be measured is proportional to the excitation level.

Removable screw terminal connections of Laurel transmitters

LT series DIN rail Transmitters & signal conditioners can be interfaced to a wide range of sensors and transducers using one of seven available plug-in signal conditioner boards. The transmitters duplicate the high performance (high accuracy and high read rate) and extensive programmable features of Laureate 1/8 DIN digital panel meters, counters, and timers. They utilize the same signal conditioners boards, much of the same firmware, and Laurel's free Windows-based Instrument Setup Software. They come in a compact DIN rail mount package with detachable screw-clamp connectors for easy wiring.

The LT series Transmitters feature isolated, user-selectable analog outputs (4-20 mA, 0-20 mA, 0-10V, or -10V to +10V), an RS232 or RS485 serial data interface, and dual 120 mA solid state AC/DC relays. Most models, except those with temperature or AC RMS signal conditioners, include an isolated 5, 10, 12, or 24 Vdc transducer excitation output.

Connecting Laureate LT Transmitters to a Local Area Network (LAN)

Up to 30 Laureate LT Transmitters and/or Digital Panel Meters can be configured for RS485 and daisy-chained to an LT Transmitter for seamless LAN integration. Alternatively, Laurel LTE series Ethernet transmitters can connect directly to a LAN via an Ethernet cable. Setup for both configurations is streamlined using Laurel’s free Instrument Setup Software, which simplifies node discovery and transmitter configuration.

Flexible Communication Options for LT Transmitters

Laureate Transmitters can be equipped with Laurel communication boards to support various interfaces and protocols. These include serial interfaces with ASCII or Modbus RTU protocols, and Ethernet interfaces with web access, ASCII, or Modbus TCP/IP protocols, ensuring versatile connectivity for your commercial applications.

Laurel network with Ethernet-to-analog converter board

DC voltage input signal transmitter

Analog Input Range Resolution Accuracy Input Ohms
DC Voltage ±200.00 mV 10 µV 0.01% FS ± 2 cts 1 GΩ
±2.0000 V 100 µV 0.01% FS ± 2 cts 1 GΩ
±20.000 V 1 mV 0.01% FS ± 2 cts 10 MΩ
±200.00 V 10 mV 0.01% FS ± 2 cts 10 MΩ
±600.0 V* 100 mV ± 0.4 V 10 MΩ
* Range ETL certified to ±300.0 V
Recalibration: All ranges are calibrated at the factory. Recalibration is recommended every 12 months.

DC current input signal transmitter

Analog Input Range Resolution Accuracy Input Ohms
DC Current ±2.0000 mA 0.1 µA 0.01% FS ± 2 cts 100 Ω
±20.000 mA 1.0 µA 0.01% FS ± 2 cts 10 Ω
±200.00 mA 10 µA 0.01% FS ± 2 cts 1 Ω
±5.000 A 1 mA ± 10 mA 0.01Ω
Recalibration: All ranges are calibrated at the factory. Recalibration is recommended every 12 months.

A-to-D Conversion
Technique Concurrent Slope™ (Pat 5,262,780)
A-to-D rate 60/s at 60 Hz, 50/s at 50 Hz
Output update rate 56/s at 60 Hz, 47/s at 50 Hz
Display update rate 3.5/s at 60 Hz, 3/s at 50 Hz
Accuracy
Error at 25°C 0.01% FS ± 2 counts (except 5A range)
Span tempco 0.003% of reading/°C
Zero tempco 0.1 count/°C
Noise Rejection
CMR, DC to 60 Hz 130 dB
NMR at 50/60 Hz 90 dB with min filtering
Maximum Signal
Max applied voltage 600 Vac for 20, 200 and 300 V ranges, 125 Vac for other ranges
Overcurrent protection 25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A
Analog Output (standard)
Output Levels 4-20 mA, 0-20 mA, 0-10 Vdc, -10 to +10Vdc (user 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
Serial Data Output (standard)
Signal Types RS232 or RS485 (half or full duplex), jumper selectable
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 RTU, Modbus ASCII, Custom ASCII
Modbus Compliance Modbus over Serial Line Specification V1.0 (2002)
RS232/485 Connector Screw terminals for easy daisy chaining
Digital Addresses 247 for Modbus, 31 for Custom 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
Excitation Output (standard)
5 Vdc 5 Vdc ± 5%, 100 mA (jumper selectable)
10 Vdc 10 Vdc ± 5%, 120 mA (jumper selectable)
12 Vdc 12 Vdc ± 5%, 100 mA (jumper selectable)
24 Vdc 24 Vdc ± 5%, 50 mA (jumper selectable)
Output Isolation 50 Vdc from signal ground
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 at 24V 1.5W typical, 3W with max excitation output
Environmental
Operating Temperature -40°C to 70°C (-40°F to 158°F)
Storage Temperature -40°C to 85°C (-40°F to 185°F)
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.
Mechanical
Enclosure Rugged black polycarbonate housing material
Mounting 35 mm rail per DIN EN 50022
Dimensions 129 x 104 x 22.5 mm case
Connectors Detachable screw clamp connectors meet VDE / IEC / UL / CSA standards. RJ45 jack for Ethernet
Tightening Torque Screw terminal connectors: 5 lb-in (0.56 Nm)
Weight Complete transmitter: 183 g (6.5 oz)
General
Programming Utilize Laurel's free Instrument Setup Software, which runs on a PC under MS Windows. 
Security Lockout options available using Laurel's free Instrument Setup Software.
Warranty 3 years parts & labor
Recalibration: All ranges are calibrated at the factory. Recalibration is recommended every 12 months.

Transmitter Pinout

Laureate LT transmitter pinout

 

Free Instrument Setup Software for Series 2 Laureates

Digital Panel Meter
1/8 DIN Digital Panel Meters DIN Rail Transmitters

Free Downloadable Windows-based Instrument Setup (IS) software (Data Interface Board Required) for use with our programmable Digital Panel Meters, Scale Meters, Counters, Timers, Remote Displays, and Transmitters, are an easy method to set up Laureate 1/8 DIN digital panel meters, counters, timers, remote displays, and DIN-rail transmitters, as explained in the Instrument Setup Software Manual. Laureate 1/8 DIN instruments can also be set up from the front panel, as explained in their respective Owners Manuals. Instrument Setup software is of benefit whether or not the PC is connected to the instrument.

  • When the PC is connected to the instrument, Instrument Setup software can retrieve the setup file from the instrument or open a default setup file or previously saved setup file from disk View Setup, then provides graphical user interface (GUI) screens with pull-down menus applicable to input, display, scaling, filtering, alarms, communications, analog output, and front panel lockouts. Fields that are not applicable to the instrument as configured are either left out or grayed out. Clicking on any item will bring up a detailed Help screen for that item. After editing, the setup file can be downloaded, uploaded to the instrument, or saved to a disk. The same setup file can then be downloaded into multiple instruments.
  • When the PC is not connected to the instrument, the above GUI screens can be used to set up a virtual instrument. The setup file can then be saved to disk. Switching toView Menu then brings up a screen with the required front panel programming steps. This view can be printed out for use at the instrument site and to serve as a hard copy record.

    Download Free Instrument Setup Software


Installation

Set User Account Control (UAC) of MS Windows to "Never notifiy me" so that Instrument Setup Software can create directories. The UAC change screen can be reached as follows:

  • Under Windows 7, click on the Windows Start button in the lower left of the desktop and enter "UAC" in the search field.
  • Under Windows 8, navigate to Control Panel, then to the "User Accounts and Family Safety" section, and click on "Change User Account Control Settings."
  • Under Windows 10, click on the Windows Start button in the lower left of the desktop, then on "Settings", and enter "UAC" in the search field.
  • Reboot your computer for the changed UAC setting to take effect.
Meter board with USB Type-B connector

RJ11-to-DB9 cable with rear view of DB9 connector to PC

Laurel USB cable, P/N CBL05

RS232 cable, meter to PC, P/N CBL01

Laureate 1/8 DIN Laureate instruments must be equipped with a serial communications board and be connected to the computer via a serial communications cable. The connection can be via RS232, RS485, USB or Ethernet. Following setup, the serial communications board may be removed from the instrument if desired. The wiring of the RS232 cable is illustrated above with end views of the two connectors.

Laureate LT Series transmitters come standard with a 3-wire serial interface, which can be jumpered for RS232 or RS485.
Laureate LTE Series transmitters come standard with an Ethernet interface.

Meter Setup Screens

Click on any of the reduced screens below for a full-size screen view, then click on the Back button of your browser to return to this page. The screens examples below are for a fully-loaded Series 2 Digital Panel Meter (DPM), which is connected to the PC via RS232. If the meter is a Series 1 meter (pre-2007), this is sensed by the software, and somewhat different screens are brought up. Please see Series 1 setup screens.

Laurel Dual Channel Pulse Input Rate Meter
Welcome Screen
From the computer desktop, click on Start > Programs > IS2 > IS2. Or click on the IS icon on your desktop. This splash screen will be displayed for three seconds. The software revision number is in the lower right.
more
Communications Selection Screen
Specify your desired communication protocol and the serial communications bus type, which should match the jumper setup of the instrument. Select None if the PC is not connected to the instrument.
more
Establish Communications Screen
If you selected RS-232, you will be asked to specify the PC Com Port and Baud Rate, which should match the jumper setup of the instrument. Click on Establish. With the right settings, the Communications Established field will light up in green, and the Meter Type will be recognized. If so, click onMain Menu.
more
Main Menu Screen
Click on File > Default Setup to retrieve the default setup file from disk for your type of meter. Click on File > Open Setupto retrieve a previously saved setup file from disk or on File > Save Setup to save your edited setup file to disk. Click onDPM > Get Setup to retrieve the setup file from your meter or on DPM > Put Setup to download your edited setup file into the meter.
more
DPM Input + Display Setup Screen
From the Main Menu, click on View > Setup, then on theInput+Display tab. You can now specify the meter hardware, signal type, display mode, and functions of control inputs A and B. Clicking on any item brings up a pull-down menu with the available choices.
more
DPM Scaling Setup Screen
Click on the Scaling tab, which provides three scaling methods to relate the signal to the displayed reading: 1) Scale and Offset method, 2) Coordinates of two points method, and 3) Reading Coordinates of Two Points method. The last method uses actual high and low signals, and the computer will prompt you.
more
DPM Filter Setup Screen
Click on the Filter tab, which allows you to specify the digital filter time constant (if any), the adaptive filter threshold, and whether Peak / Valley values are filtered or unfiltered. As for all setup screens, clicking on the F1 key while an item is highlighted brings up a Help screen for that item, as illustrated.
more
DPM Relay Alarms Setup Screen
Click on the Relay Alarms tab, which allows you to set up Alarms 1 and 2 for the optional dual relay output board. Clicking on any of the four numeric fields changes these to green and brings up a special field to enter the desired numeric value, which is tied to the displayed reading.
more
DPM Communications Setup Screen
Click on the Communications tab so set up serial communications. In particular, you can special the Serial Protocol and the meter address if multiple meters are to be addressed on the same serial data line.
more
DPM Analog Output Setup Screen
Click on the Analog Out tab so set up the optional analog output board. Three output ranges are selectable, the endpoints of which can be tied to user-specified High and Low readings.
more
DPM Lockouts Setup Screen
Click on the Lockouts tab to check off menu items which will no longer be accessible from the front panel of the meter. This will simplify meter operation and prevent unintended setup changes.
more

Meter Setup Utilities

DPM Front Panel Setup Screen
As an aid to programming the meter from the front panel when a serial connection is not available, you can return to the Main Menu and click on View > Menu. The required sequence of front panel screens will then be displayed. Click on any step in the sequence for the meaning of each digit, as illustrated for the FILtEr step. For a hardcopy, simply press on Print.
more
DPM Jumper Setup Screen
Specify your desired communication protocol and the serial communications bus type, which should match the jumper setup of the instrument. Select None if the PC is not connected to the instrument.
more
DPM Jumper Setup Screens
Click on any of the displayed plug-in boards, and you will be presented with the jumper positions and electrical connections for your selected board. This minimizes the need to refer to the printed manual.
more
DPM Commands Screen
This page allows you set up external input, serial communications, an analog output proportional to the display (optional), and lockouts for Laureate digital counters. The grayed out area at the top right of the screen applies to Laureate remote displays.
more
Graphical Output Screens (not available with Ethernet)

From the Main Menu, click on Readings if your PC is connected to the meter. A pull-down menu then offers three choices: ListPlot and Graph.

  • List presents the latest readings in a 20-row by 10-column table. Press Pause at any time to freeze the display. This is one method to capture peak readings.   
  • Plot generates a plot of readings vs. time in seconds. It effectively turns the DPM-PC combination into a printing digital oscilloscope.
    more 
  • Graph generates a histogram where the horizontal axis is the reading and the vertical axis is the number of occurrences of readings. The display continually resizes itself as the number of readings increases.
    more
DPM Calibration Screens
Click on the Scaling tab, which provides three scalClick on the Scaling tab, which provides three scaling methods to relate the signal to the displayed reading: 1) Scale and Offset method, 2) Coordinates of two points method, and 3) Reading Coordinates of Two Points method. The last method uses actual high and low signals, and the computer will prompt you.
more
Frequency Meter Calibration Screen
Calibration of the quartz crystal of the Laureate frequency meter requires the input of a known frequency from a calibrator. Apply the frequency, then enter the frequency in Hertz. Calibration will be automatic, with storage of the calibration factor stored in non-volatile memory.
more

 

Dimensions

Laurel transmitter case

Dimensioned CAD assembly drawings in EPRT, STEP, x_t, .dwg, pdf file formats: Laureate-transmitter-case.zip (zipping prevents browser from opening CAD files as text files).

 

 

CLB02

USB-to-RS232 Adapter Cable

CBL02
$47.00

CBL04

RS232 Cable for LT Transmitters

CBL04
$47.00
Ordering Guide
Part Number as Configured: LT20DCV1
Price as Configured: $334.00

Click on the Option Board Links for More Product Information

Base Item
$164.00
Main Board
$0.00
Extended allows up to 180 data points for custom curve linearization and a rate derived from consecutive readings.
$33.00
Power (Isolated)
$89.00
$89.00
Signal Input (Isolated)
DC Voltage Ranges (DC Voltage ranges are jumper selectable)
$81.00
$81.00
$81.00
$81.00
$81.00
$81.00
DC Current Ranges (DC Current ranges are jumper selectable)
$81.00
$81.00
$81.00
Note: All ranges are factory calibrated and user selectable
$81.00
Part Number as Configured:
LT20DCV1
Price as Configured:
$334.00
Quantity:
- +
Extended Price:
$334.00
More Information...