LTM-TI Modbus & Serial
Output Transmitter
for Time Interval of Periodic Events From
from 1 µs to 199.999 s. Resolution to 0.2 µs.
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.
For periodic events with
width from 1 µs to 199.999
s.
Transmitted 6-digit decimal reading.
Resolution to 0.2 µs
Rep rated to 250 kHz
Inputs from NPN or PNP proximity
switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up
to 250 Vac.
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 time interval transmitter)
Options:
Low voltage
power, 10-48 Vdc or 12-30 Vac.
Description
The
Laureate LTM TI serial output transmitter is designed for periodic time events and
can transmit pulse width or time delay between individual pulses to a
resolution of 0.2 µs. It can also transmit average pulse width or average time delay between multiple
pulses.
Time interval is measured
between inputs on channels A and B. Timing starts when a pulse is applied
to Channel A (selectable positive or negative edge), and ends when a pulse is
applied to Channel B (selectable positive or negative edge). In case of a single pulsed
signal, the A and B inputs can be tied together. A positive or negative slope may be
selected to start timing, and the opposite slope must be selected to stop timing.
Timing is achieved by counting 5.5 MHz clock pulses. Multiple integral
time intervals are averaged over a gate time which is selectable from 10
ms to 199.99 s and also controls the maximum output rate.
The dual-channel signal
conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from
12 mV to 250 Vac. Jumper selections
provide optimum operation for different sensor types and noise
conditions. A built-in 5V, 10V or 24V dc
excitation supply can power proximity switches and other sensors, and eliminate the need
for an external power supply.
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-TI 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-TI Modbus & Serial I/O Transmitter
for Time Interval of Periodic Events
Pulse Input
Types
Ch A Frequency, Max
Ch B Frequency, Max
Signal Ground
Minimum Signal
Maximum Signal
Maximum Frequency
Contact Debounce
Time
Base Accuracy
Span Tempco
Long-term Drift
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
±1 ppm/°C (typ)
±5 ppm/year
Time Interval Mode
Timing Start
Timing Stop
Periodic Timing Interval
Gate Time
Time Before Zero Output
Channel
A pulse, + or - edges
Channel B pulse, + or - edges
Gate time + 30 ms + 0-2 time intervals
Selectable 10 ms to 199.99 s
Selectable 10 ms to 199.99 s
Resolution
0 - 199.999 s
0 - 99.9999 s
0 - 9.99999 s
0 - .999999 s
0 - .099999 s
1
ms
100 µs
10 µs
1 µs
0.2 µs (after averaging)
Serial Data Output
(standard)
Signal levels
Data Rates
Output Isolation
Serial Protocols
Devices on RS48 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
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
Typical Applications
Time Interval Mode for Time Delay
For periodic pulses applied to A and B channels, time
delays can be measured down to 0.2 µs resolution from the rising or falling edge of A to
the rising or falling edge of B (selectable).
Time Interval Mode for Pulse Width
The width of periodic pulses (t1 or t2) can be measured by
tying the A and B channels together. As for time delay, readings are averaged over a
user-selectable gate time.
Timing Process Dynamics with a Panel Meter and Time
Interval Meter
The start and stop pulses used for timing can be generated
by the dual relay board in a Laureate panel meter or digital counter. For instance,
the start and stop pulse edges can be created as temperature passes two alarm setpoints,
or temperature cycles in a hysteresis control mode.
Replacing an Oscilloscope with a Laureate
Time Interval Meter
An oscilloscope is great for viewing and
timing pulses in a lab. However, in fixed installations where digital
timing accuracy and control outputs are required, a low-cost Laureate time
interval meter will be the instrument of choice. Resolution to 0.2 µs is
feasible.
Instrumenting a Pulsed Laser System
Some of the many possibilities in instrumenting a pulsed
laser system with Laureate dual-channel counters and transmitters: elapsed time, number
of pulses, pulse width, pulse separation, duty cycle, and pulse rep
rate.
Pinout LTM-TI Modbus & Serial I/O Transmitter
for Time Interval of Periodic Events
Ordering
Guide LTM-TI Modbus & Serial I/O Transmitter
for Time Interval of Periodic Events Click
on the radio buttons to build a model number with pricing.
The
Laureate
LTM TI serial output transmitter is designed for periodic time events and
can transmit pulse width or time delay between individual pulses to a
resolution of 0.2 µs. It can also transmit average pulse width or average time delay between multiple
pulses. 
The dual-channel signal
conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from
12 mV to 250 Vac. Jumper selections
provide optimum operation for different sensor types and noise
conditions. A built-in 5V, 10V or 24V dc
excitation supply can power proximity switches and other sensors, and eliminate the need
for an external power supply.
