Laurel Electronics LT: 4-20 mA & Serial Data Output Transmitter for Average Time of Periodic Events - Manual

LAUREL ELECTRONICS INC. , 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
4-20 mA & Serial Data Output Transmitter
for Average Time of Periodic Events
Features
• Transmits average time of periodic events with width from 1 µs to 199.999 s
• Resolution to 0.2 µs, rep rated to 250 kHz
• Inputs from NPN or PNP proximity switches, contact closures, digital logic, or
magnetic pickups down to 12 mV.
• 4-20 mA or 0-10V transmitter output, jumper selectable, isolated
• Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
• RS232 or RS485 serial data output, half or full duplex, isolated
• Modbus RTU, Modbus ASCII or Laurel ASCII protocol
• 5V, 10V or 24V dc transducer excitation output, isolated
• Dual solid state relays for alarm or control, isolated
• Universal AC power, 85-264 Vac, or low voltage power, 10-48 Vdc or 12-32 Vac
• DIN rail mount housing only 22.5 mm wide, detachable screw-clamp connectors
Description
The Laureate time interval transmitter can transmit pulse width
or time delay between individual pulses to a resolution of 0.2 µs
for periodic events. 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 condi-
tions. 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.
Standard features of Laureate transmitters include:
• 4-20 mA, 0-20 mA or 0-10V 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 a reading from -99,999 to +99,999 counts
that is also transmitted digitally. Output isolation from signal
and power grounds eliminates potential ground loop problems.
The supply can drive 20 mA into a 500 ohm (or lower) load for
10V compliance, or 10V into a 5K ohm (or higher) load for 2
mA compliance.
• Serial communications output, isolated. User selectable
RS232 or RS485, half or full duplex. 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.
• Dual solid state relays, isolated. Available for local alarm or
control. Rated 120 mA at 130 Vac or 170 Vdc.
• Universal 85-264 Vac power. Low-voltage 10-48 Vdc or
12-32 Vac power is optional.
Easy Transmitter programming is via Laurel's Instrument
Setup Software, which runs on a PC under MS Windows. This
software can be downloaded from our website at no charge. The
required transmitter-to-PC interface cable is available from Laurel
(P/N CBL04).