Laureate™ Time Interval Meter

Signal conditioner board for Laureate stopwatch meter

The Laureate A-to-B Time Interval Meter can display pulse width or time delay between individual pulses to a resolution of 0.2 µs. It can also display 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 display update time.

Time interval can be displayed in seconds, milliseconds, or microseconds with 6-digit resolution. In the typical application, time is displayed in milliseconds with 1 µs resolution. For times less than 100 ms, display resolution down to 0.2 µs can be achieved by applying a multiplier of 10, moving the decimal point by one position, and averaging many time intervals.

Highly accurate rate can be displayed by taking the inverse of time. Extensive arithmetic capabilities allow display in engineering units, such as meters/sec. An Extended main board version offers all features of Standard main board plus rate based on 1/time.

Signal conditioner board for Laureate stopwatch meter 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.

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.

Features

Times periodic events with width from 1 µs to 199.999 s
Display resolution to 0.2 µs
Rep rates 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
Trigger 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)

Specifications

Display
Readout	6 LED digits, 7-segment, 14.2 mm (.56"), red or green.
Range	-999999 to +999999
Indicators	Four LED lamps
Inputs
Types	AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups.
Signal Ground	Common ground for channels A & B
Channel A Freq.	0 Hz to 1 MHz
Channel B Freq.	0 Hz to 250 kHz
Minimum Signal	Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V).
Maximum Signal	250 Vac
Noise Filter	1 MHz, 30 kHz, 250 Hz (selectable)
Time Interval Mode
Timing Start	Channel A pulse, + or - edges
Timing Stop	Channel B pulse, + or - edges
Periodic Timing Interval	Gate time + 30 ms + 0-2 time intervals
Gate Time	Selectable 10 ms to 199.99 s
Time Before Zero Output	Selectable 10 ms to 199.99 s
Resolution
0 - 199.999 s	1 ms
0 - 99.9999 s	100µs
0 - 9.99999 s	10 µs
0 - .999999 s	1 µs
0 - .099999 s	0.2 µs
Accuracy
Time Base	Crystal calibrated to ±2 ppm
Span Tempco	±1 ppm/°C (typ)
Long-term Drift	±5 ppm/year
Power
Voltage, standard	85-264 Vac or 90-300 Vdc
Voltage, optional	12-32 Vac or 10-48 Vdc
Frequency	DC or 47-63 Hz
Power consumption (typical, base meter)	1.2W @ 120 Vac, 1.5W @ 240 Vac, 1.3W @ 10 Vdc, 1.4W @ 20 Vdc, 1.55W @ 30 Vdc, 1.8W @ 40 Vdc, 2.15W @ 48 Vdc
Power Isolation	250V rms working, 2.3 kV rms per 1 min test
Maximum Signal
Max applied voltage	600 Vac for 20, 200 and 300 V ranges, 125 Vac for other ranges
Current protection	25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A
Power
Voltage, standard	85-264 Vac or 90-300 Vdc
Voltage, optional	12-32 Vac or 10-48 Vdc
Frequency	DC or 47-63 Hz
Power Isolation	250V rms working, 2.3 kV rms per 1 min test
Excitation Output (standard)
5 Vdc	5 Vdc ± 5%, 100 mA
10 Vdc	10 Vdc ± 5%, 120 mA
24 Vdc	24 Vdc ± 5%, 50 mA
Output Isolation	50 Vdc to meter ground
Analog Output (optional)
Output levels	4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable)
	4-20 mA, 0-20 mA, 0-10V (dual-output option)
Current compliance	2 mA at 10V ( > 5 kΩ load)
Voltage compliance	12V at 20 mA (< 600Ω load)
Scaling	Zero and full scale adjustable from -99999 to +99999
Resolution	16 bits (0.0015% of full scale)
Isolation	250V rms working, 2.3 kV rms per 1 min test
Relay Outputs (optional)
Relay types	2 Form C contact relays or 4 Form A contact relays (NO) 2 or 4 Form A, AC/DC solid state relays (NO)
Current Ratings	8A at 250 Vac or 24 Vdc for contact relays 120 mA at 140 Vac or 180 Vdc for solid state relays
Output common	Isolated commons for dual relays or each pair of quad relays
Isolation	250V rms working, 2.3 kV rms per 1 min tes
Serial Data I/O (optional)
Board selections	RS232, RS485 (dual RJ11 or RJ45 connectors), USB, Ethernet, USB-to-RS485 converter, Ethernet-to-RS485 converter
Protocols	Modbus RTU, Modbus ASCII, Modbus TCP (Ethernet), Laurel ASCII
Data rates	300 to 19200 baud
Digital addresses	247 (Modbus), 31 (Laurel ASCII),
Isolation	250V rms working, 2.3 kV rms per 1 min test
Environmental
Operating temperature	0°C to 55°C
Storage temperature.	-40°C to 85°C
Relative humidity	95% at 40°C, non-condensing
Protection	NEMA-4X (IP-65) when panel mounted
Signal Connections

Applications

Application Example

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.
Rate Based on 1 / Time
	The Extended stopwatch meter can be programmed to display highly accurate rate based on elapsed time. A pulse or switch closure can initiate timing, while another pulse or switch closure stops timing. The meter can be programmed with multipliers to display rate in appropriate engineering units, such as meters/sec, for any time duration.
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.
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