NEWS ARCHIVE INDEX

PI660 Version Capabilities November 2002

Pacific and DaqScribe Deliver Another Aerojet System November 2002

Time Alignment of High and Low Speed Data November 2002

Battery Powered Data Acquisition for Mobile Testing March 12, 2001

New Transducer Amplifier-Digitizer with Remote Sensing May 5, 2000

PI660 VERSION CAPABILITIES
Concord, CA, November 2002

With Version 8 of PI660 Pacific restructured the available software packages. There are now just four products. PI660SP is the basic recording and display software. PI660XP is the "Professional" package and now includes the CMD and MATH extension that were previously extra cost options. PI660XPS is the Server version of "Professional" and now includes one Client license. PI660C is the display and recording Client.

PACIFIC AND DAQSCRIBE DELIVER ANOTHER AEROJET SYSTEM
Concord, CA, November 2002

In October 2002, along with daqScribe as system integrator, Pacific delivered the fifth data acquisition system to Aerojet in Sacramento and received an order for the sixth system, which will be delivered in February 2003. The recently delivered system is for the P Zone, which is a horizontal test facility for large solid rocket motors. A successful first test of an Atlas IV booster took place in early November. The recently ordered system is for G Zone, which is a test stand for small liquid motors. The fully integrated systems approach used by daqScribe and Pacific means that system installation and commissioning can be accomplished in less than one week allowing the facility to run its first test in the same month the system is delivered. This compares to several weeks of installation and commissioning for the previous systems. The Aerojet engineers tell us they have never seen higher quality data than they are getting from their 6000s.

TIME ALIGNMENT OF HIGH AND LOW SPEED DATA
Concord, CA, November 2002

The initial Aerojet system in E Zone that has been in service for over 12 months was the first application to simultaneously record 1 MS/s and 25 MS/s data streams for low-speed and high-speed data. The low-speed measurement system is a Pacific 6000 with the usual GPIB interface that records data to a hard drive. In this case low-speed is a relative term in that 1 MS/s is over 4 times faster than most competitive data acquisition systems. The high-speed system uses Pacific's 6030 transducer signal conditioning with 50 kHz bandwidth installed in the 6000 mainframe and slave enclosures with low-speed channels. Analog outputs of the 6030s are digitized by ICS 610 Sigma-Delta ADCs at 100 kS/s per channel and recorded on a 3-disk, 90 GB RAID.

Recording data on two physical media presents the problem of how to time align low and high-speed data. Pacific's engineers came up with a straightforward solution to this problem. Aerojet provides a TTL firing signal when the engine is ignited. The 6000 system uses one digital input on a 6040 to record the firing signal along with other low-speed data. The same firing signal is digitized and recorded on the RAID by one of the ICS 610 high-speed channels. When the data files are exported the channel with the digitized firing signal is analyzed for the location where the signal rose above a TTL threshold. This data point corresponds to the firing signal recorded by the 6040 in the low-speed data file.

The time of each data point is adjusted relative to the firing signal, which represents zero time. If the absolute time is important it can be derived from an IRIG or GPS source. Two methods are available to do this. The first method uses an IRIG or GPS source installed on the PCI bus in the controlling computer. When the recording of data begins decoded time is inserted in the header of the low-speed data file. Since the sampling rate and order is known and consistent the absolute time of each data point may be calculated. The recorded time differs from the time of the first sample by the latency incurred transferring data across the GPIB bus and may be in the order of 20-50 mS. This error may be reduced by adjusting for the actual latency. The second method uses a 6047 IRIG time decoder installed in a 6000 Mainframe or Slave enclosure channel slot. Time data is recorded along with other low-speed data. This method has no latency error and provides an accuracy equal to the time of the highest sample rate used for low-speed data, i.e. 100 microseconds for 10 kHz.

BATTERY POWERED DATA ACQUISITION FOR MOBILE TESTING
Concord, California, March 12, 2001

Pacific Instruments, Inc., designer and manufacturer of high performance transducer data acquisition systems, announces a battery operated model for automotive and other portable applications. The new 6005 Mainframe with space for 72 channels can be expanded to over 2,000 channels by adding slave enclosures. PI660, Pacific's acquisition and display software, and a laptop computer complete the system for mobile acquisition and display of transducer data.

Designed to meet the rugged performance and operational needs of vehicular testing, the new Mainframe operates from 10 to 20 VDC for current generation or 20 to 56 VDC for future generation vehicles. It has all connections and controls on one surface for placement in tight locations. The HS-GPIB interface, used for programming, control and recording of data, provides data rates up to 1 Million samples per second. PI660, a Windows 98/NT/2000 application, records data to disk while providing the operator with real-time viewing of the measurements in both time and frequency domains.

The mainframe is configured for specific transducers by plug-in signal conditioning modules. Input types range from simple 2-wire voltage to complex 8-wire full bridge and include digital inputs and outputs as well as rotational and time measurements. Capabilities include voltage and current excitation, remote sensing, voltage and shunt calibration, automatic zero and balance, gains from .01 to 5,000, four and six pole filters, 100 kHz bandwidth, simultaneous sampling and 16-bit resolution.

PI660 makes application of the 6005 mainframe to mobile testing easy reliable. For example, in over-the-road tests it can show upper and lower limits on a scrolling chart enabling the driver to match a speed profile by keeping the "bug" within the limits. At the same time continuously monitored alarm levels can alert the operator to measurement channels that need attention and can trigger saving pre and post-alarm data in a dedicated hardware history buffer. Out-of-limit measurements can automatically generate control outputs that can be used to limit or terminate testing preventing damage to expensive test equipment.

Programming for a test can be done in any database or spreadsheet program that makes Microsoft Access compatible files. Simply download the database file to program the mobile system. While on the road, programming changes and operator control use PI660's built-in, interactive menus and toolbars. When a test is completed data can be replayed to graphical displays or exported in ASCII and binary formats compatible with most analysis programs.

NEW TRANSDUCER AMPLIFIER-DIGITIZER WITH REMOTE EXCITATION SENSING
Concord, California, May 5, 2000

Pacific Instruments announces a new four-channel transducer signal conditioning amplifier-digitizer that uses remote sensing to precisely regulate excitation voltage applied to transducers. Used in Series 6000 data acquisition systems, Model 6032 is specifically designed for high accuracy strain gage and bridge transducer measurements.

For structural testing of airframes, vehicles and ships, transducers are usually located at some distance from their signal conditioning. Unless corrected for, IR losses in the excitation lines create substantial measurement errors. Pacific's new 6032 Four-Channel Transducer Amplifier-Digitizer eliminates this problem by regulating the excitation voltage at the transducer. Additionally the excitation voltage may be continuously monitored and an alarm generated if any channel is outside of its prescribed limits.

Software configures the 6032 for quarter, half or full bridge transducer eliminating the usual jumpers or soldering and need for precision bridge completion resistors. The 8-wire, shielded input provides dedicated leads for high-accuracy shunt calibration. Automatic zero and balance replace the tedious manual adjustments usually associated with bridge transducers.

The new transducer amplifier is entirely programmable. Excitation is programmed in 1-Volt steps from 0 to 12 Volts. Gain is programmable from 1 to 5,000 with 0.05% accuracy. A four-pole, low-pass filter provides bandwidths from 1 Hz to 1 kHz with selection of filtered or wideband output. End-to-end voltage calibration using a certified standard provides traceable measurement accuracy.

A 16-bit ADC digitizes the transducer signals at programmable sample rates up to 15K per channel. Individual sample & hold amplifiers provide 50-nanosecond time correlation channel to channel. In addition to the digitized output each channel has a high-level, ±10 Volt, output for analog monitoring and recording.

Other new features in the 6032 are hardware-based limit alarms and peak detection. Two sets of programmed high and low alarm levels are monitored for each channel. An alarm violation may be used to automatically activate digital outputs that can control external equipment or provide operator warning. Hardware-based alarms provide the fastest detection of conditions that could damage an expensive test article. Peak detection records the highest signal level during a calibration or data run for automatically setting the optimum gain.

A fourteen-inch high, rack-mounting mainframe holds up to 64 channels. It has a high-speed IEEE-488 interface for programming and data output that supports data rates up to 1M samples per second. Slave enclosures may be added for up to 4096 channels.

Windows 98 and NT software supports the 6032 for setup, data recording and display. A component level DLL supports applications in Visual Basic, LabVIEW, Excel and other Windows programming languages.

The new high-performance strain gage and transducer digitizer joins other Series 6000 input modules that digitize thermocouples, RTDs, potentiometers, accelerometers, LVDTs, voltage, current and RPM. This modular design is used to provide fully functional, Windows-based turnkey systems for structural, aerodynamic and environmental testing.

Model 6032 is available now from Pacific Instruments, Inc.