 |
LTM-R
Modbus & Serial Output Transmitter
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
 |
|
Features
|
|
Description The Laureate LTM-R serial output, pulse input transmitter accepts two independently scalable input channels A & B from a wide range of pulse sources, such as NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC voltages to 250 Vac. Input frequencies can range from 0.005 Hz to 1 MHz. Arithmetic functions A+B, A-B, AxB, A/B or A/B-1 to track the sum, difference, product, ratio, or draw of both input channels are available with the Extended main board. These arithmetic operations can be applied to scaled rates, scaled totals, square root of rates, totals after square root extraction, custom curve linearized rates, or totals after custom curve linearization.
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-R include:
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). |
Exceptional Accuracy and
Stability.
Laureate pulse
input frequency and rate transmitters determine
frequency by taking the inverse of period as measured with a calibrated
quartz crystal time base. This results in extremely accurate and stable
6-digit internal readings (±999,999 counts), which are then processed in
software. The update rate of the transmitter output is a programmed gate time + 30 ms + 0-2 signal periods. For
pulse rates of
60 Hz and above, the update rate would be 20 per second. Such fast update rates
are ideal for alarm and control.
Specifications
LTM-R Modbus & Serial I/O Transmitter
for Ratio, Product, Sum or Difference
| Pulse Input | |
|
Types Ch A Frequency, Max Ch B Frequency, Max Signal Ground Minimum Signal Maximum Signal Maximum Frequency Contact Debounce Time Base Accuracy Arithmetic Functions |
AC,
pulses from NPN, PNP transistors, contact closures, magnetic pickups. 1 MHz. 250 kHz. Common ground for channels A & B. Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V). 250 Vac 1 MHz, 30 kHz, 250 Hz (selectable). 0, 3, 50 ms (selectable). Quartz crystal calibrated to ±2 ppm. A+B, A-B, AxB, A/B, A/B-1 |
| Serial Data Output (standard) | |
|
Signal levels Data Rates Output Isolation Serial Protocols Devices on RS-485 Line Modbus Addresses Modbus Modes Modbus Compliance |
RS232 or RS485 (half 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 (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) | |
|
Output levels Output isolation |
5V@100 mA, 10 @120 mA, 24V@50 mA (jumper
selectable) 50V from signal ground |
| 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 Frequency Power Isolation |
95-240 Vac ±10% or 90-300 Vdc (DC operation not UL approved) 12-30 Vac or 10-48 Vdc 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 plug connectors |
| Environmental | |
|
Operating Temperature Storage Temperature Relative Humidity |
0°C to
70°C -40°C to 85°C 95% at 40°C, non-condensing |
| Application Examples of Ratio Meters | |
Controlling the Mixing Ratio of Two Fluids |
|
 |
Transmitting and alarming the input flow rate ratio of two fluids (gas or liquid) allows these to be mixed in a predetermined ratio in continuous processes. The sensing element is normally a turbine flow meter, which outputs pulses at a frequency proportional to flow rate. The A/B ratio can also be transmitted for totalized rate (or delivered volume). |
Comparing Fluid Inflow & Outflow |
|
 |
The ratio of the inflow and outflow rates of a tank is a measure of the relative filling or emptying rate. The same transmitter can also be programmed to transmit the net inflow or outflow rate in flow units, or to transmit totalized inflow our outflow in volume units. Any of these parameters can be alarmed using the dual relay board and be transmitted via 4-20 mA. |
Controlling Coating Thickness on a Film |
|
 |
In this application, Channel A measures the rate at which a coating material is applied, as measured by a flow meter, while Channel B measures the speed of the film based on pulses from a proximity switch. Transmitting and alarming the A/B ratio assures that an even thickness of coating material is applied as the speed of the film is varies. |
Synchronizing Two Conveyor Lines |
|
 |
The dual-channel Laureate transmitter can measure the speed of conveyor lines by using the output of proximity switches which sense gear teeth or spokes of rotating drive wheels. Transmitting the speed ratio of two lines allows line speeds to be adjusted so that material arrives at work stations when needed. |
Measuring Draw for Elongation |
|
 |
Draw (Ch A / Ch B - 1) can be used to indicate the elongation of films compressed between rollers, the shrinkage films, and the RPM difference of rollers whose speed is varied to maintain tension. The high resolution of Laureate dual channel transmitters is ideal for comparison of rates that are close to each other. |
Pinout
LTM-R Modbus & Serial I/O Transmitter
for Ratio, Product, Sum or Difference
Ordering
Guide
LTM-R Modbus & Serial I/O Transmitter
for Ratio, Product, Sum or Difference
Click
on the radio buttons to build a model number with pricing.
|
Resource Pages |
