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.