Laurel

Time Interval of Periodic Events Modbus or Laurel ASCII Protocol Serial I/O Transmitter

(From from 1 µs to 199.999 s. Resolution to 0.2 µs. DIN Rail mounted, digitally programmable.)
Features
  • Selectable Modbus or Laurel ASCII protocol.
  • For periodic events with width from 1 µs to 199.999 s.
  • Resolution to 0.2 µs.
  • Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
  • Isolated 5V, 10V or 15V dc excitation output to power transducers.
  • Easy setup using Laurel's PC-based Instrument Setup Software.
  • Modbus RTU or ASCII modes, 2-wire connection, up to 247 digital addresses.
  • Transmitted 6-digit decimal reading.
  • Rep rated to 250 kHz.
  • Trigger on positive or negative pulse edges.
  • DIN rail mount package only 22.5 mm thick.
  • Optional dual solid state relays for alarm or control.
Description

timers1The Laureate TM Series serial output transmitter for periodic time events can transmit 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. Selectable full-scale ranges go from 0.099999 sec with 0.2 µs resolution (after averaging) to 199.999 sec with 1 ms resolution.

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.

freqbd2The 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 isolated 5V, 10V or 15V dc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.

Laureate TM Series transmitters send data as a serial digital signal. RS485 or RS232 signal levels are jumper selectable and can each be associated with either the Modbus protocol or Laurel’s simpler Laurel ASCII protocol.

Modbus protocol operation is fully compliant with the Modbus Over Serial Line Specification V1.0 (2002) for 2-wire, half-duplex connection. This includes RTU or ASCII modes, addressing of up to 32 devices per RS485 line without a repeater, and up to 247 digital addresses. Modbus operation allows devices by different manufacturers to be connected in parallel and be addressed using the same protocol.

Laurel’s 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’s datalogging software.

Transmitter programming is via the unit's three-terminal serial port using Laurel's PC-based Instrument Setup Software. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Laurel (P/N CBL03). Laurel's serial output transmitters and meters can also be part of PC-based data logging systems using Laurel's Datalogging Software, which operates under the Laurel ASCII Protocol. A single software command switches between the Modbus and Laurel ASCII Protocols.

Options include dual solid state relays for local alarm or control and an isolated 4-20 mA or 10V (selectable) analog output, effectively providing a linearized analog transmitter output that tracks the reading that would be transmitted digitally. The analog output provides 12-bit (4096 step) resolution of the output span and is ultra-linear to within one bit. Its accuracy is ±0.05% of span for all signal types, except for AC rms, where accuracy is ±0.1%. Output isolation from signal and power grounds is provided by a separate on-board power supply, which can drive 20 mA into a 500 ohm load for 10V compliance. Output isolation eliminates problems caused by ground loops.

Laureate transmitters are housed in a 35 mm DIN rail case that is only 22.5 mm (0.89") thick. Signal connections are via detachable screw clamp plug connectors.

Specifications- Laureate Serial I/O Transmitter, Stopwatch Input

Pulse Input
Types AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups.
Ch A Frequency, Max 1 MHz.
Ch B Frequency, Max 250 kHz.
Signal Ground Common ground for channels A & B.
Minimum Signal Nine ranges from (-12 to +12 mV) to (+1.25 to +2.1V).
Maximum Signal 250 Vac
Maximum Frequency 1 MHz, 30 kHz,  250 Hz (selectable).
Contact Debounce 0, 3, 50 ms (selectable).
Time Base Accuracy Quartz crystal calibrated to ±2 ppm.
Span Tempco ±1 ppm/°C (typical)
Long-term Drift ±5 ppm/year
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 100 µs
0 - 9.99999 s 10 µs
0 - .999999 s 1 µs
0 - .099999 s 0.2 µs (after averaging)
Serial I/O (standard)
Signal levels RS485 (default) or RS232 (jumper selectable)
Data Rates 300, 600, 1200, 2400, 4800, 9600, 19200 baud
Output Isolation 250V rms working, 2.3 kV rms per 1 min test.
Serial Protocols Modbus RTU, Modbus ASCII, Laurel ASCII (selectable)
Devices on RS-485 Line 32 max without a repeater.
Modbus Addresses 247 max
Modbus Modes RTU or ASCII, 2-wire.
Modbus Compliance Modbus over Serial Line Specification V1.0 (2002).
Transducer Excitation Outputt(standard)
Jumper Selection 1 10V @ 60 mA, isolated to 50V from signal ground
Jumper Selection 2 5V @ 50 mA, isolated to 50V from signal ground
Jumper Selection 3 15V @ 60 mA, non-isolated
Dual Relay Output(optional)
Relay Type Two solid state relays, SPST, normally open, Form A
Load rating 120 mA at 130 Vac or 170 Vdc, 28 ohms series resistance.
Analog Output (optional)
Output Levels 0-20 mA, 4-20 mA or  0-10 Vdc (selectable)
Compliance, 4-20 mA 10V ( 0-500 ohm load )
Compliance, 0-10V 2 mA ( 5 kOhm load )
Output Resolution 12 bits (4,096 steps)
Output Accuracy ±0.05% of output span
Output Isolation 250V rms working, 2.3 kV rms per 1 minute test
Power Input
Standard power 95-240V AC ±10% or 90-300V DC
Low power option 12-30V AC or 10-48V DC
Frequency DC or 47-63 Hz
Power Isolation 250V rms working, 2.3 kV rms per 1 min test.
Mechanical
Case Dimensions 120 x 101 x 22.5 mm
Case Mounting 35 mm rail per DIN EN 50022
Electrical Connections Detachable screw clamp plug connectors
Environmental
Operating Temperature 0°C to 70°C
Storage Temperature -40°C to 85°C
Relative Humidity 95% at 40°C, non-condensing

Application Example

Time Interval Mode for Time Delay
timers1 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
timers2 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
timers6 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
timers5 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
timers4a
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.
 
Laureate Serial Output Transmitters Pulse Input for Frequency, Rate or Period
(shown with optional analog output and dual relay output)
tx-ta-dual1
Transmitter Powering a Single Sensor
tx-ta-dual2a tx-ta-dual3a
Transmitter Powering Two Sensors Transmitter with Active or Passive Sensors
Purchase
5672 Bolsa Avenue Huntington Beach, CA 92649 - USA - Ph (714) 622-2000 - Fax (714) 622-2001