Laurel Electronics LT: 4-20 mA & Serial Data Output Transmitter for Time of Single or Accumulated 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 Time of Single or Accumulated Events
Features
• Transmits single event time or accumulated time of all events
• Timing from 0.2 µs to 999,999 hrs
• 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 stopwatch transmitter outputs isolated analog
and serial data signals whose values track the time of single
events which produce start and stop pulses, or the accumulated
time of multiple events. It can also time the width of a single
pulse. The highest resolution is 0.2 µs, making the transmitter
ideal for fast events. The longest timing interval is 999,999 hrs.
For long events, the analog output is updated continuously during
timing. There are two primary timing modes:
• A-A Stopwatch Mode: Time is measured between a start
pulse and a stop pulse, both on Channel A, from either the
positive or negative edges.
• A-B Stopwatch Mode: Time is measured between a start
pulse on Channel A (positive or negative edge) and a stop
pulse on Channel B (positive or negative edge). This mode
allows inputs from different sources. In addition, the A and B
inputs can be tied together to start the stopwatch with one
polarity and stop it with the other polarity.
Event time (Item #1) is measured by counting 5.5 MHz clock
pulses from a calibrated quartz crystal. The stopwatch output is
updated during timing at a rate controlled by a gate time, up to
25/sec. Time is reset to zero when the next start pulse occurs.
Accumulated time (Item #2) from multiple events up to 999,999
hours is also tracked and can be transmitted.
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 AC
signals from 12 mV to 250 Vac. Jumper selections provide opti-
mum operation for different sensor types and noise conditions.
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).