 |
LTM-VF Modbus & Serial
Output Transmitter
& Totalizer for 0-1 mA, 4-20 mA
or 0-10V
Scalable
to flow rate
or total flow from process signals.
DIN Rail mounted, digitally
programmable.
|
Standard Features
|
-
Selectable Modbus
or Laurel ASCII protocol.
- Modbus
RTU or ASCII modes, 2-wire connection,
up to 247 digital addresses.
- Output rate from
0-1 mA, 4-20 mA or 0-10V analog signals.
- Output totalized rate from
0-1 mA, 4-20 mA or 0-10V analog signals.
- Selectable square root extraction for differential
pressure flow transducers.
- Output scalable to six transmitted digits:
- Span adjust from 0 to ±999,999.
- Zero adjust from -999,999 to
+999,999.
- Exceptional accuracy:
±0.005% of
input span ±1 count
- Output update rate: 25/sec.
- Peak value capture.
- DIN rail mount package only 22.5 mm thick.
- Detachable screw clamp plug connectors.
- Easy setup with PC-based
Instrument Setup Software.
- 5V, 10V or 24V dc sensor excitation
output, isolated.
- Dual solid state relays for alarm or control,
isolated.
- 0-10V, 4-20 mA or 0-20 mA analog output,
isolated.
- Universal AC power, 95-240 Vac ±10%
- Priced at only $235
(basic totalizer transmitter)
Options:
- Extended Main Board for custom curve linearization,
time based on rate (1/rate).
- Low voltage
power, 10-48 Vdc or 12-30 Vac.
|
Description
The Laureate
LTM-VF serial output
totalizing transmitter accepts 0-1
mA, 4-20 mA or 0-10V signals from flow meters and other transducers, such
as watt meters, to track rate or totalized rate.
-
With a Standard Main Board,
the transmitter output can track rate (such as gallons per
minute or watts) or totalized rate (such as gallons or kilowatt hours) whether the transducer output is linear or requires
square root extraction (differential pressure flow transducers).
-
With an Extended Main Board, the transmitter
can also perform custom curve linearization (provided by a curvilinear spline fit with up to 180
data points), display 1/ rate (such as the time it takes a conveyor to
pass through an oven), and perform batch control for repetitive fill
operations. Such
applications typically make use of optional dual solid state relays,
which are available as options. External reset of totals is provided by a
special connector.
 The V-to-F signal conditioner
board converts the full-scale 0-1 mA, 4-20 mA or 0-10 V analog signal to a frequency of
10 kHz to 110 kHz. This frequency is determined by measuring period over a selected gate time
(from 10 ms to 200 s) and taking the inverse of period. At
the lowest frequency of 10 kHz and the minimum gate time of 10 ms, the
transmitter is capable of
25 updates per second. Scaling is done mathematically. Totals are stored in nonvolatile memory in case of
power loss.
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-VF 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).
|
Specifications
LTM-VF Modbus & Serial I/O Transmitter &
Totalizer for 0-1 mA, 4-20 mA or 0-10V Inputs
|
Analog Input |
0-1 mA |
4-20 mA |
0-10 V |
Input resistance
Max current or voltage |
182 ohms
37 mA |
9 ohms
160 mA |
1 Mohm
600 V |
Input Resolution
Span Tempco
Zero Tempco
Accuracy at 25°C
Read Rate |
6 digits
±0.0025%
R/°C
±0.0005 FS/°C
±0.005% FS ±1 count
25/sec (typical) |
|
Serial Data Output
(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
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 (optional) |
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 |
Pinout
LTM-VF Modbus & Serial I/O Transmitter &
Totalizer for 0-1 mA, 4-20 mA or 0-10V Inputs
Ordering
Guide
LTM-VF Modbus & Serial I/O Transmitter &
Totalizer for 0-1 mA, 4-20 mA or 0-10V Inputs
Click
on the radio buttons to build a model number with pricing.
|
