LTM-P Modbus & Serial I/O Transmitter, Process Signal Input

LTM-P Modbus & Serial Output Transmitter
for Process Signal Input
Scalable for process signals requiring zero and span adjustment.
Ideal for pressure & flow. DIN Rail mounted, digitally programmable.

Standard Features

200 mV, 2V, 20V, 200V, 300V & 600V DC voltage ranges.

2, 20, 200 mA and 5A DC current ranges.

All ranges factory calibrated.

Digital span adjust from 0 to ±99,999

Digital zero adjust from -99,999 to +99,999

RS232 or RS485 serial communications, half or full duplex, isolated.

Modbus RTU, Modbus ASCII or Laurel ASCII protocol.

Output update rate to 60/sec.

4-20 mA, 0-20 mA or 0-10V transmitter output, jumper selectable, isolated.

Easy setup with PC-based Instrument Setup Software.

DIN rail mount housing only 22.5 mm wide.

Detachable screw-clamp connectors.

5V, 10V or 24V dc transducer excitation output, isolated.

Dual solid state relays for alarm or control, isolated.

0-10V, 4-20 mA or 0-20 mA analog output, scalable, isolated.

Universal AC power, 95-240 Vac ±10%

Priced at only $235 (basic process transmitter)
Options:

Extended main board for custom curve linearization & rate from successive readings.

Low voltage power 10-48 Vdc or 12-30 Vac.

Description

The Laureate LTM-P 4-20 mA output, process input transmitter provides six DC voltage input ranges and four DC current input ranges for use with a wide range of transducers whose output requires zero and span adjustment. All ranges are factory calibrated and jumper selectable. The two most sensitive voltage ranges, 200 mV and 2V, provide a high input impedance of 1 Gohm to minimize the load on the voltage signal.

Fast read rate at up to 50 or 60 conversions per second while integrating the signal over a full power line cycle is provided by Concurrent Slope (Pat 5,262,780) analog-to-digital conversion. High read rate is 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. The internal digital readings and analog output can be individually selected to be either unfiltered or filtered.

LTM Series serial output transmitters send data via an isolated serial port, which is user configurable for RS232 or RS485 and full or half duplex operation. 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 allows up to 31 Laureate devices to be addressed on the same RS485 data line. It is simpler than the Modbus protocol and is recommended when all devices are Laureates. It also allows use of Laurel Datalogging Software.

Standard features of Model LTM-P include:

Serial data output, isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Laurel ASCII protocol.
Dual solid state relays for control or alarm, isolated. Rated 120 mA at 130 Vac or 170 Vdc.
Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
Analog transmitter output, 16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
Universal AC power supply for 95-240 Vac ±10%.

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).

Pinouts
LTM-P Modbus & Serial I/O Transmitter for Process Signal Input

Specifications
LTM-P Modbus & Serial I/O Transmitter for Process Signal Input

Analog Input	Range	Input Ohms
Voltage	200.00 mV 2.0000 V 20.000 V 200.00 V 600.0 V	1 Gohm 1 Gohm 10 Mohm 10 Mohm 10 Mohm
Current	2.0000 mA 20.000 mA 200.00 mA 5.000 A	100 ohms 10 ohms 1 ohm 0.01 ohm
Input Resolution Input Accuracy Update Rate, Max Max Applied Voltage Current Protection	16 bits (65,536 steps) ±0.01% of full scale ± 2 counts 50/sec at 50 Hz, 60/sec at 60 Hz 600 Vac for 20, 200 & 600 V ranges, 125 Vac other ranges 25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5A
Transducer Excitation Output (standard)
Output levels Output isolation	5V@100 mA, 10 @120 mA, 24V@50 mA (jumper selectable) 50V from signal ground
Serial Data Output (standard)
Signal Types Data Rates Output Isolation Serial Protocols Modbus Modes Modbus Compliance Digital Addressing	RS232 or RS485 (half or full duplex) 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 RTU or ASCII Modbus over Serial Line Specification V1.0 (2002) 247 Modbus addresses. Up to 32 devices on RS485 line w/o a repeater.
Dual Relay Output (standard)
Relay Type Load rating	Two solid state relays, SPST, normally open, Form A 120 mA at 130 Vac or 170 Vdc, 28 ohms in series
Analog Output (standard)
Output Levels Compliance, 4-20 mA Compliance, 0-10V Output Resolution Output Accuracy Output Isolation	4-20 mA, 0-20 mA, 0-10 Vdc (jumper selectable) 10V ( 0-500 ohm load ) 2 mA ( 5 kOhm load or higher) 16 bit DAC ±0.02% of output span plus conversion accuracy 250V rms working, 2.3 kV rms per 1 minute test
Power Input
Standard power Low power option Power frequency Power Isolation	95-240 Vac ±10% or 90-300 Vdc (DC operation not UL approved) 10-48 Vdc or 12-30 Vac 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-clamp plugs
Environmental
Operating Temperature Storage Temperature Relative Humidity	0°C to 70°C -40°C to 85°C 95% at 40°C, non-condensing

Custom curve linearization

Using a linearizing digital panel meter or transmitter

A Laureate process meter or transmitter with the Extended main board option allows exceptionally accurate custom curve linearization. For setup, up to 180 data points can be entered into a spreadsheet. The system then creates multiple non-linear spline-fit segments, which provide much better accuracy than linear segments. One application, as illustrated, is the readout of volume of irregularly shaped tanks based on measured liquid level or pressure. Altimeters and thermistors are further applications.

Ordering Guide
LTM-P Modbus & Serial I/O Transmitter for Process Signal Input
Click on the radio buttons to build a model number with pricing.

Quantity
Transmitter Type	LTM Laureate Transmitter, Modbus or Laurel ASCII Protocol	$235
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 95-240 Vac ±10% 1 12-30 Vac or 10-48 Vdc	NC $30
Setpoint Output	0 None 2 Isolated Dual Solid State Relays	NC NC
Analog Output	0 None 1 4-20 mA, 0-10V	NC NC
Signal Input	Process Signals (e.g., 4-20 mA, 0-5 V) P Default Scaling. 4-20 mA in = 0-100.00 out P1 Custom Scaling In the write-in field of your invoice, specify min input, min reading; max input, max reading.	NC $10
Signal Input	Note: The same DC signal conditioner can be user configured for process, strain or potentiometer follower signals, as well as DC Volts or DC Amps. It is precalibrated in EEPROM for all DC Volt and DC Amp ranges listed for DC transmitters.	NC $10
Accessories	CBL04 RS-232 cable, LTM to computer or USB adapter CBL02 USB to RS-232 cable adapter	$19 $39

Configured model number	LTM2000P
Configured price per model	$235
Quantity	1
Extended price	$235

LTM-P Modbus & Serial Output Transmitter for Process Signal Input Scalable for process signals requiring zero and span adjustment. Ideal for pressure & flow. DIN Rail mounted, digitally programmable.

LTM-P Modbus & Serial Output Transmitter
for Process Signal Input
Scalable for process signals requiring zero and span adjustment.
Ideal for pressure & flow. DIN Rail mounted, digitally programmable.