L-FR, Laurel, Laureate Digital Stopwatch & Timer


- Dual-Channel Pulse Input Signal Conditioner
- Times single or cumulative events from 1µs to 999,999 hrs
- Timing resolution to 0.2 µs
- Selectable HH.MM.SS clock forma or H, M or S decimal format
- Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac
- Triggers on positive or negative pulse edges
- Universal 85-264 Vac / 90-300 Vdc or 10-48 Vdc / 12-32 Vac power
- Transducer excitation output (isolated)
- Wide choice of options:
- - 2 or 4 relays, mechanical or solid state (isolated)
- - 1 or 2 analog outputs (isolated)
- - Serial data I/O: Ethernet, USB, RS485, RS232 (isolated)
The FR dual-channel signal conditioner board 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 isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.
- A-A Stopwatch Mode. Time can be 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 can also be 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.
- Rate Based on 1/Time Mode. Highly accurate rate can be displayed by taking the inverse of time. Extensive arithmetic capabilities allow display in engineering units, such as meter/sec. This mode requires use of an Extended counter.
Display. The event time (Item #1) may be displayed as a decimal number with six-digit resolution. The longest single-event timing interval is 999,999 hours. The highest resolution is 0.2 µs. The event time may also be displayed in HH.MM.SS clock format with 1 s resolution. The stopwatch display is updated during timing at a rate controlled by a gate time, up to 25/s. It is reset to zero when the next start pulse occurs. Accumulated time from multiple events (Item #2) is also tracked and may be displayed up to 999,999 hours.
The FR dual-channel signal conditioner board accepts inputs from proximity switches with a 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 isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.
Digital filtering is selectable for electrically noisy environments, including a batch averaging filter and an adaptive moving average filter which provides a choice of 8 time constants from 80 ms to 9.6 s. When a significant change in signal level occurs, that filter adapts by briefly switching to the shortest time constant to follow the change, then reverts back to the selected time constant. In a selectable Auto filter mode, the filter time constant is automatically selected based on detected signal noise.
Designed for system use. Optional plug-in boards for communications and control include Ethernet and other serial communication boards, dual or quad relay boards, and single or dual isolated analog output boards. Laureates may be powered from 85-264 Vac or optionally from 12-32 Vac or 10-48 Vdc. The display is available with red or green LEDs. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can be locked out for simplified usage and security. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.
Laureate™ 1/8 DIN Case: For Laureate Digital Panel Meters, Counters, Timers & Remote Displays
Key Features:
- Meets 1/8 DIN Standard.
- Installs from front of panel.
- Short depth behind the panel: only 4" (102 mm) plus connectors.
- Understated 0.157" (4 mm) thick bezel.
- Meets NEMA 4X (IP-65) for high-pressure wawshdon when panel mounted.
- Screw clamps connectors meet VDE / IEC / UL / CSA safety standards.
- Rugged GE Lexan® housing material.
- Safety certified per EN 61010-1.
Maximum panel thickness: 4.5 mm (0.18")
Weight of base meter: 210 g (7.4 oz) typical (DPM, counter, timer, 6-digit remote display)
Weight of option boards: 30 g (1.0 oz) typical per board (analog output, relay output, communications)
Stopwatch Mode |
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The stopwatch mode is used to time single events to one microsecond resolution between start and stop pulses on the same channel. The width of a single waveshape can be measured by tying the A and B channels together. |
Timing Process Dynamics |
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The start and stop pulses used for timing can be generated by the dual relay board in a Laureate analog panel meter or digital counter. For instance, the start and stop pulse edges can be created as temperature passes two alarm setpoints, or as temperature cycles in a hysteresis control mode. |
Rate Based on 1 / Time |
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The Extended stopwatch meter can be programmed to display highly accurate rate or speed based on time. For example photodetectors on Channels A and B can provide timing pulses as a fast-moving object breaks two light beams, and the meter can then display speed in engineering units such as ft/sec or m/sec. The display will be held until reset by an external control input. |
Replacing an Oscilloscope with a Laureate Meter |
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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 |
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Some of the many possibilities in instrumenting a pulsed laser system with Laureate dual-channel counters: elapsed time, number of pulses, pulse width, pulse separation, duty cycle, and pulse rep rate. |
L-FR Digital Stopwatch & Timer Datasheet |
L-FR, Laureate Digital Stopwatch & Timer Manual |