Laurel Electronics for Digital Panel Meters, Counters, Timers, Transmitters, Digital Displays

Digital Panel Meters - Counters - Timers
DIN Rail Transmitters - Large Digit Displays

    

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Load Cell & Microvolt Input
Modbus or Laurel ASCII Protocol Serial I/O Transmitter
 DIN Rail mounted, digitally programmable.
Exceptional accuracy at high update rates.

Features

  • Selectable Modbus or Laurel ASCII protocol.
  • Modbus RTU or ASCII modes, 2-wire connection, up to 247 digital addresses.
  • Digital span adjust from 0 to ±99,999.
  • Digital zero adjust from -99,999 to +99,999.
  • 20, 50, 100, 250 & 500 mV full scale ranges.
  • Peak value capture and auto-tare.
  • Output accuracy: ±0.01% of full scale input.
  • Update rate: to 60/sec.
  • Isolated 10V, 60 mA excitation supply to power up to two 350-ohm load cells in parallel.
  • 4- or 6-wire hookup to avoid supply and lead resistance effects.
  • DIN rail mount package only 22.5 mm thick.
  • Powered by AC or DC.
  • Detachable screw-clamp connectors.
  • Easy setup using PC-based Instrument Setup Software.
  • Optional isolated scalable analog output (4-20 mA or 0-10V).
  • Optional dual solid state relays for alarm or control.
  • Optional custom curve linearization (Extended main board).
 		Serial ASCII or Modbus Transmitter, Load Cell & Microvolt Input

CE Mark       RoHS Mark

Description

Signal Types & Ranges.  Laureate Modbus I/O load cell or microvolt input transmitters are designed for use with load cells, strain gauges and microvolt input signals where exceptional sensitivity and stability are required. A most sensitive full-scale input range ±20 mV can be scaled to ±99,999 counts. The selected input range for the full 0-20 mA output span can be as wide as ±99,999 counts or as narrow as 150 counts, limited only by considerations of electrical noise and time constants of the programmable moving average digital filter.

DIN Rail Mounting.  Laureate transmitters are housed in a 35 mm DIN rail case that is only 22.5 mm (0.89") thick. Signal connections are via detachable screw clamp plug connectors.

Modbus Compliance.  Laureate Modbus transmitters are fully compliant with Modbus over Serial Line Specification V1.0 (2002). This includes RTU or ASCII modes, 2-wire connection, up to 247 digital addresses, and up to 32 devices per RS-485 line without a repeater. For microvolt DC or load cell signal inputs, output accuracy is ±0.01% of full scale input, as provided by the 16-bit analog-to-digital converter front end. Full conversion accuracy is maintained in the Modbus output. Advanced standard features made possible with Modbus operation include peak capture, auto-tare and latched relay operation, since Reset can be provided via digital commands.

Built-in Load Cell Excitation

Load cell signal conditioner board for Transmitter, Load Cell & Microvolt InputAn isolated 10 Vdc, 60 mA excitation supply rated can power up to two 350-ohm load cells in parallel. With 4-wire load connection, the transmitter operates in a ratiometric mode to eliminate errors due to supply variations. With 6-wire load connection, it also compensates for variation in resistance of the transducer leads, thereby allowing long cable runs.

Fast Read Rate

All Laureate analog input meters and transmitters use Concurrent Slope (Pat 5,262,780) analog-to-digital conversion, which allows up to 50 or 60 conversions per second, while integrating the signal over a full power line cycle. High read rate is ideal for peak capture and for real-time computer interface and control.

Selectable Signal Filtering

The internal digital readings and analog output can be separately 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 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.

Easy Setup & Scaling

Transmitter programming is via a three-terminal RS-232 port using Laurel's PC-based Instrument Setup Software. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL03). Laurel's serial output transmitters and meters can also be part of PC-based data logging systems using Laurel's Datalogging Software, which operates under the Laurel ASCII Protocol. A single software command switches between the Modbus and Laurel ASCII Protocols.

Scale and offset can be set by either of two methods:

  • With the coordinate reading method, the Laureate reads the high and low signal values, and the user enters the desired high an low reading values. The Laureate then calculates the span multiplier and offset. This method is ideal if an external calibration reference is available.

  • With the manual coordinate method, the user enters the high and low input values in Volts plus the desired high and low reading values. This method is suitable if no external calibration reference is available.

Options

Options include dual solid state relays for local alarm or control and an isolated 4-20 mA or 10V (selectable) analog output, effectively providing a linearized analog transmitter output that tracks the reading that would be transmitted digitally. The analog output provides 12-bit (4096 step) resolution of the output span and is ultra-linear to within one bit. Its accuracy is ±0.05% of span for all signal types, except for AC rms, where accuracy is ±0.1%. Output isolation from signal and power grounds is provided by a separate on-board power supply, which can drive 20 mA into a 500 ohm load for 10V compliance. Output isolation eliminates problems caused by ground loops.

Specifications
 Laureate Serial Output Transmitter, Load Cell or Microvolt Input

Analog Input

 Range Resolution Input Ohms
Load Cell
 
 
 
  		     ±20.000 mV      
±50.0000 V
±100.00 V
±250.00 V
±500.00 V		 -99,999 to +99,999
zero adjust.
0 to ±99,999 span
adjust.		 1 Gohm
Microvolt Meter
 
 
 
  		  ±20.000 mV 
±50.0000 V
±100.00 V
±250.00 V
±500.00 V		 1 µV
2.5 µV
5.0 µV
12.5 µV
25 µV		 1 Gohm
Input Resolution
Input Accuracy
Output Update Rate, Max
Max Applied Voltage		 16 bits (65,536 steps)
±0.01% of full scale input (determined by ADC).
50/sec at 50 Hz, 60/sec at 60 Hz.
100 V
Serial I/O (standard)
Signal levels
Data Rates
Output Isolation
Serial Protocols
Devices on RS-485 Line
Modbus Addresses
Modbus Modes
Modbus Compliance		 RS485 (default) or RS232 (jumper selectable)
300, 600, 1200, 2400, 4800, 9600, 19200 baud
250V rms working, 2.3 kV rms per 1 min test.
Modbus RTU, Modbus ASCII, Laurel ASCII (selectable)
32 max without a repeater.
247 max
RTU or ASCII, 2-wire.
Modbus over Serial Line Specification V1.0 (2002).
Transducer Excitation Output (standard)
Jumper Selection 1
Jumper Selection 2
Jumper Selection 3		 10V @ 60 mA, isolated to 50V from signal ground
5V @ 50 mA, isolated to 50V from signal ground
15V @ 60 mA, non-isolated
Dual Relay Output (optional)
Relay Type
Load rating		 Two solid state relays, SPST, normally open, Form A
120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance.
Analog Output (optional)
Output Levels
Compliance, 4-20 mA
Compliance, 0-10V
Output Resolution
Output Accuracy
Output Isolation		 0-20 mA, 4-20 mA or  0-10 Vdc (selectable)
10V ( 0-500 ohm load )
2 mA ( 5 kOhm load )
12 bits (4,096 steps)
±0.05% of output span
250V rms working, 2.3 kV rms per 1 minute test
Power Input
Standard power
Low power option
Frequency
Power Isolation		 95-240V AC ±10% or 90-300V DC
12-30V AC or 10-48V DC
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test.
Mechanical
Case Dimensions
Case Mounting
Electrical Connections		 120 x 101 x 22.5 mm
35 mm rail per DIN EN 50022
Detachable screw terminal connectors
Environmental
Operating Temperature
Storage Temperature
Relative Humidity		 0°C to 70°C
-40°C to 85°C
95% at 40°C, non-condensing

Pinout
 Laureate Serial Output Transmitter, Load Cell or Microvolt Input
(shown with optional analog output and dual relay output)

Pinout, Serial ASCII or Modbus Transmitter, Load Cell & Microvolt Input

For 4-wire load cell connection, jumper Pin 1 to Pin 2, and Pin 5 to Pin 6.

Load Cell Transmitter Connections
  

4-wire load cell bridge connection of a load cell transmitter
In 4-wire connection, the excitation and sense lines are tied together. The meter can make ratiometric corrections for supply voltage variations, but not compensate for variations in lead resistance. This connection is often used with short cable runs.

6-wire bridge connection of a load cell transmitter
In 6-wire connection, the sense lines are separate from the excitation lines, thereby eliminating effects due to variations in lead resistance. This allows long cable runs in outdoor environments with temperature extremes.

Up to six 350-ohm load cell bridges connected in parallel to a Laureate load cell transmitter
For large scales, up to four 350 ohm load cells in parallel can be powered by a single Laureate transmitter at 5V excitation. The excitation and sense points of the four bridges are connected in parallel through a summing box.

Ordering Guide
Modbus or Laurel ASCII Protocol Serial I/O Transmitter,
Load Cell or Microvolt Input

Create a model number in this format: TM2020WM. This example calls out a Modbus output transmitter, standard main board, 95-240 Vac power, isolated dual solid state relays, and a load cell signal conditioner at the default setting 0-20 mV in = 4-20 mA out. Includes plug-in screw terminal connectors.
  
Transmitter
Type		 TM   Laureate Transmitter, Modbus or Laurel ASCII Protocol. $210
Main
Board		 2  Standard Main Board.
4  Extended Main Board.
Note: Extended allows custom curve linearization and rate from successive readings.		 NC
$40
Power 0  Isolated 95-240 Vac & 90-300 Vdc
1  Isolated 12-30 Vac & 10-48 Vdc.		 NC
$30
Setpoint
Output		 0  None.
2  Isolated Dual Solid State Relays.		 NC
$30
Analog Output 0  None.
1  4-20 mA, 0-10V.		 NC
$25
Signal
Input		 Load Cells (6-wire ratio)
 WM    Default Scaling. 0-20 mV in = 4-20 mA out.
WM1  Custom Scaling.
In the write-in field of your invoice, specify min input, min reading; max input, max reading. Full-scale input is 20-500 mV. Includes 10V excitation for up to four 350-ohm load cells in parallel.		  $55
Accessories CBL03  RS-232 cable, TM to computer.
CBL02  USB to RS-232 cable adapter.		 $19
$39
 
Laurel Electronics domestic orders Order from distributors for shipment to USA or Canada.
Laurel Electronics international orders Order online for international shipment.

 

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Laurel Electronics, Inc.
Industrial Instrumentation & Displays
3183-G Airway Avenue
Costa Mesa, CA 92626, USA
Phone: (714) 434-6131
Fax:     (714) 434-3766

  
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