Extending the NI Timing Platform with GPS, IRIG, and PXI Express

Accurate and reliable timing is essential when measuring signals and coordinating motion. Without timing, noise mapping using microphone arrays would be impossible; stimulus and response tests would be painfully slow; and multiple motors, without coordination, would cause crashes. To prevent these types of problems, NI is adding GPS, IRIG, and PXI Express to its timing platform.   

 

Because timing is critical to measurement and automation systems, National Instruments has been creating innovative timing and synchronization tools for more than 20 years. Hardware innovations include the RTSI bus (1987), the system timing controller ASIC (1994) for NI data acquisition products, and PXI (1997). Recently, NI introduced the Synchronization and Memory Core (SMC) device (2003) for NI modular instruments and PXI Express (2006) with enhanced timing and synchronization features built into the backplane. NI has also introduced many software innovations focused on timing. Even LabVIEW 1.0 (1986) featured timing primitives. LabVIEW Real-Time (1998) and LabVIEW FPGA (2003) are innovations for deterministic and hardware-timed applications. The LabVIEW timed loop synchronizes multiple software loops to a common timebase.   

 

The latest NI timing tools include the new NI PXI-6682 GPS, IEEE 1588, and IRIG time code and synchronization module, which provides GPS time, location, and velocity; IRIG-B decoding; and an improved implementation of IEEE 1588 (see right sidebar). The PXI-6682 is designed for timestamping and triggering measurements or events across large physical objects such as airplanes or bridges or geographically distributed systems such as power grids or devices for seismic monitoring. In addition, you can use the PXI-6682 to synchronize the start of distributed PXI systems at specified future times.    

 

NI is also releasing the NI PXIe-6672 timing and synchronization module, the industry’s first PXI Express timing and synchronization controller (see left sidebar). This module is designed to provide routing of internal and external timing signals, including the star trigger bus, as well as multichassis synchronization and synchronization with external systems and instruments. The NI PXIe-6672 works with all PXI and PXI Express modules in a PXI Express hybrid chassis.    

 

Both modules use the new NI-Sync 3.0 API to interface with NI LabVIEW and LabWindows™/CVI software as well as other programming languages. The NI-Sync driver provides automatic routing capabilities and integration with NI-DAQmx along with using NI Measurement & Automation Explorer  (MAX) for configuration. The new hardware and software products are part of the NI commitment to providing leading timing and synchronization functionality.   

 

Learn more about PXI timing and synchronization modules.

 

 

 

NI PXIe-6672 Timing and Synchronization Module  

 

 

• PXI star trigger controller
• 10 MHz TCXO reference (1 ppm)
• Reference clock import and export
• PLL capabilities
• DDS clock generation
• DC to 105 MHz, 1 μHz resolution
• Software trigger generation
• RoHS compliance (lead free)  

 

NI PXI-6682 GPS, IEEE 1588, and IRIG Time Code and Synchronization Module

 

 

 

 

• IEEE 1588, GPS, IRIG-B, PPS time references
• Synchronization accuracy

 – GPS: ±100 ns peak, <13 ns standard deviation

 – IEEE 1588: ±47 ns peak, <10 ns standard deviation

• Integrated 12-channel, parallel tracking
• GPS receiver GPS stationary and mobile mode support
• 3 PFI SMBs, star and PXI trigger sources for triggering and time-based I/O
• IEEE 1588 grandmaster and slave support
• 10 MHz clock routing
• Clock generation DC to 1.5 MHz
• TCXO reference (1 ppm)
• Future time clocks and triggers
• RoHS compliance (lead free)  

 

The mark LabWindows is used under a license from Microsoft Corporation.

 

This article first appeared in the Q4 2007 issue of Instrumentation Newsletter.

 

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