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Products > Ethernet Data Acquisition Systems > Model 7400  


Model 7400, High-Speed Ruggedized 16-Ch Strain/Bridge/Voltage Ethernet DAS


Features

  • 16-Channels Strain Gage, Bridge, Voltage Transducers, Dynamic Strain or IEPE
  • Ethernet control and data interface
  • Real time temperature compensated (Gain & Excitation) from -20°C to +50°C
  • 0.05% or better accuracy over full gain & temperature range
  • 90 kHz analog bandwidth, gain 1 to 1,000
  • 24-Bit A/D programmable up to 200kS/s per channel
  • FIR filter, 128 tap
  • IRIG A, B & G time decoding and recording
  • 1 μS synchronized sampling of multiple enclosures
  • Ruggedized for tough environments
  • 20 to 30 Volt DC power

Description

Pacific’s Ruggedized Model 7400 increases the bandwidth and sample rates of the popular 7200 ruggedized data systems. A network appliance, each module conditions, amplifies and digitizes the outputs of up to sixteen strain gage, bridge or voltage transducers. The rugged enclosure is designed for installation in wind tunnels, engine test stands and other facilities where it is desired to locate the DAS close to the test article, ultimately reducing installation and cable costs as well as improving signal quality and reliability.

Fully self-contained, the 7400 provides transducer excitation, bridge completion and balance. The transducer output is amplified, filtered to remove signal components that could produce alias errors and digitized to 24-bit resolution. The digitized transducer output is digitally processed providing multiple sample rates, an 80 dB/octave FIR filter and 32-bit floating point output format in millivolts referred to input, millivolts referred to output or user defined engineering units.

Three models are available that differ in their excitation and signal conditioning capabilities. Model 7416 for strain gage and bridge transducers has programmable voltage excitation, bridge completion for 120 and 350 Ohm strain gages, shunt calibration and automatic balance. Model 7420 is similar but provides regulated power for transducers with internal electronics. Model 7418 is for voltage inputs. The amplified transducer signals are digitized, processed and output at up to 200,000 samples per second, as selected for individual channels. A digital signal processor (DSP) provides low-pass filtering selectable from 10 Hz to 50 kHz with 80 db/octave roll-off.

Each module has a 1 Gigabit Ethernet interface for control and data output, which simplifies system wiring and provides remote and distributed operation. IRIG time may be employed to synchronize sampling on multiple modules within 10 microseconds, or a TTL timing signal may be used to achieve better than 1 microsecond time alignment. Multiple modules with up to 4,096 channels may be connected on a single Ethernet LAN.

The module enclosure features interchangeable end plates that provide fully sealed, ambient air or forced air cooling. Forced air cooling provides the capability to operate over a wide temperature range according to application requirements. Occupying less than 500 cubic inches and weighing less than 14 pounds, the 7400 system can be installed in locations previously not suitable for data acquisition systems. The Ethernet interface and IRIG timing make it easy to distribute modules throughout the test facility, minimizing sensor cabling and installation costs.

The 7400 does not sacrifice performance for size or portability; it features higher accuracy than most systems designed for a laboratory environment. Accuracy is better than 0.05% for gains up to 200 and 0.1% for gains above 200 over the temperature range -20°C to +50°C, which can be extended to higher temperatures by forced air cooling.

Model 7400 is supported by Pacific’s PI770 software that provides a ready-to-run application and an SDK for user program development. Calibration and performance verification is accomplished by PANEL72 Maintenance and Calibration software. The ACS2000 Automatic Calibration System automates performance verification and periodic instrument calibration.







Input  · Excitation/Transducer Power  · 7424 Current Excitation  · Amplifier  · Filter  · Digitizer  · Time Synchronization  · Accuracy  · Calibration  · Interface / Communications  · Mechanical  · Ordering Information 

Input

Configuration

7416: Six-wire input, signal input (2), excitation (2), excitation sense (2) and shield. Programmable bridge completion for half bridges and 120 Ohm and 350 Ohm quarter bridges.
7418: Two-wire input, signal input (2) and shield.

7420: Four-wire input, signal input (2), transducer power (2) and shield.

7424: Six-wire input, signal input (2), excitation (2), excitation sense (2) and shield. Programmable bridge completion for half bridges and 120 Ohm and 350 Ohm quarter bridges.

Input Impedance

7424: 50 Megohms, shunted by 500 pF DC coupled, 100K Ohms AC coupled.
50 Megohms shunted by 500 pF.

Input Stability

±0.02% for 8 hours, ±0.005%/ºC.

Input Protection

±50 Volts differential, ±50 Volts common mode without damage.

Bridge Balance

7416: Automatic by program control. Balance accuracy ±0.05% of range, ±1 mV RTO. Range set by resistor up to 25 mV/V, 2.5 mV/V (350 Ohms) installed.
7424: Automatic by program control. Balance accuracy ±0.05% of range, ±1 mV RTO.

AC Coupling

7424: Programmable AC/DC coupling with 0.68 Hz -3dB corner frequency for IEPE Transducers and dynamic strain.


Excitation/Transducer Power

Voltage Excitation

7416: Constant voltage with remote sensing. Programmable from 1 to 15 Volts with 1 mV resolution. Calibrated 1-Volt steps ±0.1%. 50 mA limited to 70 mA maximum.
7424: Constant voltage with programmable local/remote sensing and digital regulation, calibrated 1-Volt steps from 1 to 15 VDC. 50 mA limited to 90 mA maximum.

Voltage Excitation Regulation

±0.1% over input voltage range and no-load to full load.

Voltage Excitation Stability

±0.01%, 0.001%/°C

Voltage Excitation Noise

200 µV peak-to-peak, DC to 10 kHz

Transducer Power

7420: Regulated voltage. Programmable from 1 to 15 Volts in 1V steps. Regulation and stability ±1%


7424 Current Excitation

Current Excitation

16 steps, 2mA to 50mA

Compliance (Constant Current Excitation)

0.1 to 24 Volts minimum

Current Regulation

±0.01% or ±0.1µA for 10% line change

Current Excitation Noise

2 µA or 5 µV peak-to-peak DC to 10 kHz

Stability (Constant Current Excitation)

±0.01% or ±2 µA for 30 days. Temperature coefficient is less than ±0.005% or ±1 µA/ºC.


Amplifier

Input Range

7424: ±10 mV to ±10 Volts, DC or AC coupled.
±10 mV to ±10 Volts.

Gain

7424: Programmable from 1 to 1,000 with 0.02% resolution. Thirteen calibrated gain steps are provided: 1, 2, 3, 5, 10, 20, 30, 50, 100, 200, 300, 500, 1000 with ±0.05% accuracy up to Gain 200, ±0.1% accuracy above Gain 200.
Programmable from 1 to 1,000 with 0.02% resolution. Thirteen calibrated gain steps are provided: 1, 2, 3, 5, 10, 20, 30, 50, 100, 200, 300, 500, 1000 with ±0.02% accuracy.

Gain Stability

±0.01% for 30 days, ±0.001%/ºC compensated.
±0.05% for 30 days, ±0.005%/ºC without compensation.

Gain Linearity

±0.02 %

Common Mode

60 dB plus gain in dB to 110 dB, DC to 60 Hz.

Operating CM Voltage

±10 V

Zero (Amplifier)

Automatic zero to ±2 µV RTI or ±1.0 mV RTO whichever is greater.

Zero Stability

±2 µV RTI plus ±1 mV RTO over the full temperature range.

Source Current

±40 nA, ±0.4 nA/°C

Bandwidth

7424: 45 kHz (-3dB)
100 kHz (-3dB)

Noise (100 kHz)

4 µV RTI plus 0.3 mV RTO, RMS

Crosstalk

100 dB at 10 kHZ

Harmonic Distortion

90 dB at 10 kHz

Overload

Recovery time is 120 µS to within ±0.1% for a 10 times overload to ±10 Volts.


Filter

Type

Finite Impulse Response (FIR) with 128 coefficients.

Frequency

Programmable from 10 Hz to 50 kHz with 80 dB/octave attenuation above cut-off.


Digitizer

Resolution

24-bits, Sigma-Delta type.

Rate

Individual channels may be programmed to output data at rates up to 200 kHz. Supports all sixteen channels at the highest sample rate.


Time Synchronization

Source

External TTL input or IRIG A, B or G. IRIG G output provided from each 7400 for multiple module synchronization.

Time Alignment

1 µS using external TTL and 10 µS using IRIG channel to channel and module to module.

Output

Days, Hours, Minutes, Seconds, Microseconds may be output at selected positions in the data stream.


Accuracy

7300/7400 Accuracy

The system maintains ±0.05% full scale (2-sigma) uncertainty for gains up to 200 and ±0.1% full scale (2-sigma) uncertainty for gains above 200 over the operating temperature range.


Calibration

Shunt

Two steps, single shunt. Internal or external shunt connection.

Shunt Resistors

7424: 174k and 357k Ohm, ±0.1%
Installed shunt resistors provide 0.502 and 0.250, ±0.1% mV/V for 350 Ohm bridge.

Voltage (Calibration)

The output of a temperature stable, 5-Volt internal reference with ±0.01% stability, X1.0, X0.1 and X0.01 ±0.05% attenuator and 0.0015% resolution on each attenuator setting may be applied to each channel. Accuracy is ±0.2% for gains to and including 100 and ±0.3% for gains over 100. Stability is ±0.01%. Output of the internal reference can be measured on an external connector.

Zero Calibration

Amplifier input disconnected and shorted for zero calibration.


Interface / Communications

Interface

Gigabit Ethernet, TCP/IP, control and data.

Data Format

Floating point, 32-bits. Output available in engineering units, Volts or millivolts.

Operation

Supported by PI770 operational software and PANEL72 maintenance software.


Mechanical

Connectors

MIL, 1/4-turn locking

Temperature

-20°C to +50°C operating in ambient air. -20°C to +40°C operating fully sealed. Extended temperature range with forced air cooling.

Shock/Vibration

50 Gs, 11 mS all axis. MIL-STD-810F, Catagory 24.

Moisture

NEMA 13

Power (Mechanical)

20 to 30 VDC, 3A

Width

View
5.25 in

Height

View
7.75 in

Depth

View
12 in

Weight

14 lb


Ordering Information 

Ordering Information

7416 - 16-Ch Strain/Bridge Data Acquisition (DC coupled)
7418 - 16-Ch Voltage Data Acquisition (DC coupled)

7420 - 16-Ch Transducer Data Acquisition (DC coupled)

7424 - 16-Ch Strain/Bridge/IEPE Data Acquisition (AC / DC coupled)

Pacific Instruments, Inc. · 4080 Pike Lane · Concord, CA 94520 · www.pacificinstruments.com