A built-in, isolated, 10V, 120 mA excitation supply can power up to four 350-ohm load cells in parallel. Load cell connection can be via 4 or 6 wires. With 4-wire load connection, the transmitter operates in a ratiometric mode to eliminate errors due to power supply variations. With 6-wire load connection, it also compensates for lead resistance, allowing long cable runs.
Fast read rate at up to 50 or 60 conversions per second while integrating the signal over a full power line cycle are 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.
- An unfiltered selection 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. An Auto setting selects the time constant selection based on signal noise.
Standard features of Laureate LT transmitters include:
- 4-20 mA, 0-10V or -10V to +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.
- Serial communications output, 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.
- Dual solid state relays, isolated, for alarm or control. Rated 120 mA at 140 Vac or 180 Vdc.
- Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
- 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 this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL04).
Load Cell Transmitter Connections
|In 4-wire connection, the excitation and sense lines are tied together. The transmitter can make ratiometric corrections for supply voltage variations, but does not compensate for variations in lead resistance. This connection is often used with short cable runs.|
|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.|
|For large scales, up to four 350 ohm load cells in parallel can be powered by a single Laureate transmitter at 10V, 120 mA excitation. The excitation and sense points of the four bridges are connected in parallel through a summing box.|
- 4-20 mA, 0-20 mA, 0-10V or -10V to +10V transmitter output, 16 bits, isolated
- RS232 or RS485 serial data output, Modbus or Laurel ASCII protocol, isolated
- Dual 120 mA solid state relays for alarm or control, isolated
- 20, 50, 100, 250 and 500 mV full-scale input ranges
- 4 or 6-wire hookup to avoid power supply and lead resistance effects
- Digital span adjust from 0 to ±99,999, zero adjust from -99,999 to +99,999
- Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
- 10V excitation supply for up to four 350-ohm load cells in parallel
- Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
- Custom curve linearization and rate from successive readings (optional)
|Analog Input||Range||Scaling||Input Ohms||Error at 25°C|
|Load Cell Input||±20.000 mV||-99,999 to +99,999
0 to ±99,999
|1 GΩ||±0.01% of rdg
± 2 cts
|Microvolt Input||±20.000 mV||1 µV||1 GΩ||±0.01% of FS
± 2 cts
|±50.0000 mV||2.5 µV|
|±100.00 mV||5.0 µV|
|±250.00 mV||12.5 µV|
|±500.00 mV||25 µV|
|Reading Resolution||16 bits (65,536 steps)|
|Reading Accuracy||±0.01% of reading ± 2 counts in ratiometric mode,
±0.01% of full scale ± 2 counts in absolute mode
|Update Rate, Max||50/sec at 50 Hz, 60/sec at 60 Hz|
|Max applied voltage||100 V|
|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 or higher)|
|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|
|Transducer Excitation Output (standard)|
|Output Levels||5V@100 mA, 10V @120 mA, 24V@50 mA (jumper selectable)|
|Output Isolation||50V from signal ground|
|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|
|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 TCP, Modbus RTU, Modbus ASCII, Laurel ASCII|
|Modbus Compliance||Modbus over Serial Line Specification V1.0 (2002)|
|Ethernet Connector||RJ45 jack for 10/100 Base-T Ethernet cable|
|RS232/485 Connector||Screw terminals for easy daisy chaining|
|Digital Addresses||247 for Modbus, 31 for Laurel ASCII|
|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|
|Dimensions||129 x 104 x 22.5 mm case|
|Mounting||35 mm rail per DIN EN 50022|
|Electrical Connections||Plug-in screw-clamp connectors|
|Operating Temp.||0°C to 55°C|
|Storage Temp.||-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.|
|Datasheet, Manual, Mechanical and Serial I/O info.|
4-20 mA & Serial Data Transmitter for Load Cell & Microvolt Signals
- Brand: Laurel Electronics, Inc.
- Model: LT
- Availability: In Stock