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

LTS RS232/485 Serial-to-Analog Converter DIN Rail Transmitter

Converts serial input data to an isolated, scaled analog output signal.

Serial to analog transmitter


  • Converts streaming RS232 or RS485 ASCII data to an isolated, scaled 4-20 mA, 0-10 mA, 0-10V or -10V to +10V analog output.
  • Able to retrieve data from long character strings.
  • Setup using Laurel's free Instrument Setup Software.
  • Accepts Modbus or Custom ASCII protocol commands to set analog output or relay action.
  • Includes up to 1 hour of technical phone support with screen sharing.
  • Serial data rates from 300 to 9600 baud.
  • Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span.
  • Dual 120 mA solid state relays can respond to readings or to control characters.
  • Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power.
  • DIN rail mount housing only 22.5 mm wide, detachable screw-clamp connectors.
LTS6 serial to analog transmitter

The LTS serial data input, analog output transmitter accepts streaming RS232 or RS485 serial data ASCII strings from an external device, like a scale, at rates up to 9600 baud. It converts this data to an isolated, scalable 4-20 mA, 0-20 mA, 0-10V or -10V to +10V analog output. Two solid state relays are standard and can respond to readings or to received control characters. The LTS also accepts serial commands via the Modbus RTU or Laurel Custom ASCII protocols to set the analog output or relay state. The unit is housed in a transmitter case which is only 22.5 mm (0.89") thick and fits on a 35 mm DIN rail. Depending on the model, it can be powered by AC (85-264 Vac) or DC (10-48 Vdc).

Standard LTS features include:

  • Streaming serial data input, RS232 or RS485. The data to be converted to analog is specified using Laurel's free Instrument Setup Software. The user-selectable "Remote C" mode allows the number of characters in the data, preceding the data and following the data to be specified. In all cases, it is essential to know know the what ASCII characters are contained in each serial data transmission.
  • Commands via the Modbus RTU, Modbus ASCII or Custom ASCII protocols. For details, please or Modbus and Custom ASCII manuals. These commands can be used to set the analag output and the state of the unit's two relays. Modbus implementation is fully compliant with Modbus over Serial Line Specification V1.0 (2002) for operation, with up to 247 digital addresses.
  • 4-20 mA, 0-20 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 readings from -999,999 to +999,999 counts. Output isolation from signal and power grounds eliminates potential ground loops.
  • Dual solid state relays for control or alarm, isolated. Rated 120 mA at 140 Vac or 180 Vdc. The relays can respond to digital readings or to received control characters, or be commanded via the Modbus protocol or Custom ASCII protocol.
  • Transmitter programming 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 cables from the transmitters to a PC com port are available from Laurel (P/N CBL02 and CBL04).
  • Up to one hour of technical phone support. Programming requires an understanding of the ASCII characters in your streamed data. Setup assistance using screen sharing is built into the price of the LTS.

Programmable Streaming Input Modes

Six data conversion modes are user selectable to receive and process streaming data. The number of characters to be processed can be up to 7, including 6 digits and a decimal point. Include leading zeros, like 00300.0. The LTS is not plug and play. The format of the strings being received must be known in advance, including non-printing control characters. If you do not know the string format, contact tech support of the sending device's manufacturer, or use a terminal emulator program like HyperTerminal, PuTTY or RealTerm to view the actual transmitted characters.

  • Remote S processes single values without a digital address. An alarm character is optional.
  • Remote A processes single values with a digital address. An alarm character is optional.
  • Remote 1 processes the 1st of up to 4 readings embedded in a Laureate transmission.
  • Remote 2 processes the 2nd of up to 4 readings embedded in a Laureate transmission.
  • Remote 3 processes the 3rd of up to 4 readings embedded in a Laureate transmission.
  • Remote 4 processes the 4th of up to 4 readings embedded in a Laureate transmission.
  • Remote C can process readings embedden in long ASCII strings. Specify the start character at the beginning of the string, the number of characters following the start chracter to be ignored, the number of characters to be processed following the lastignored character, and the stop character at the end of the string.

Programmable Command Modes

A Master, which can be a PC, PLC or other programmable device, can send digital values to an LTS transmitter to cause it to output specifc analog signals and actuate alarms. Ether the Modbus RTU protocol or Laurel's simpler Customer ASCII protocol can be used for commands. Both support digital addressing.

  • The Modbus RTU protocol uses Function Code FC10, Holding Register 006C, and data as 4 hexadecimal bytes.
  • The Custom ASCII protocol uses the string *1K followed by the decimal reading and by <CR>
Laureate LTS Serial Input, Analog Output, DIN Rail Transmitter
Serial Data Input (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 Laurel ASCII
Analog Output (standard)
Output Levels 4-20 mA, 0-20 mA, 0-10 Vdc, -10V to +10V (user selectable)
Compliance at 20 mA 10V (0-500Ω load)
Compliance at 10V 2 mA (5 kΩ or higher load )
Output Resolution 16 bits (65,536 steps)
Output Accuracy ±0.02% of output span
Output Update Rate Determined by input data rate, max 10/sec
Output Isolation 250V rms working, 2.3 kV rms per 1 minute test
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 1.5W typical at 24V
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 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 for Laureate LTS serial-to-analog transmitter
For applications assistance, phone 714-434-6131 ext. 110, or email
Ordering Guide
Laureate LTS RS232/RS485 Serial Input, Analog Output DIN Rail Transmitter
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
Transmitter Type LTS6  RS232/RS485 in, 4-20 mA out. Includes 1 hour of phone support. $314
Power 0  85-264 Vac or 90-300 Vdc $89
1  Isolated 12-32 Vac or 10-48 Vdc $89
Add-on Options
CBL04  RS232 cable, 7ft. Connects RS232 screw terminals of LT transmitter to DB9 port of PC. $23
CBL02  USB-to-DB9 adapter cable. Includes FTDI chip for compatibility with all versions of Windows. Combination of CBL02 and CBL04 connects PC USB port to LT RS232 port. $47
Configured model number LTS60
Configured price per model $403
Quantity 1
Extended price $403
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