NI PXIe-6672 PXI Synchronization Module

The NI PXIe-6672 is a PXI Express synchronization module that serves as the primary timing and synchronization controller within PXI Express chassis. It distributes precise triggers and clocks across multiple modules while enabling multichassis synchronization and external instrument alignment. The module combines a high-stability 10 MHz TCXO with direct digital synthesis and flexible routing capabilities to meet demanding measurement and control requirements.

– Technical Specifications

Timing and Synchronization
• PXI Express System Timing Slot Controller for primary timing control
• Star Trigger (PXI_STAR): Drives up to 17 lines with <1 ns skew for trigger/clock distribution
• Trigger Bus (PXI_TRIG): Eight bused TTL lines for triggers, clocks, and handshaking signals
• 10 MHz Clock (PXI_CLK10): High-accuracy, low-jitter override of chassis reference clock
• Multichassis and external instrument synchronization support

Clock Generation and Frequency Stability
• High-Stability 10 MHz TCXO with 1 ppm frequency accuracy (vs. 25 ppm standard backplane)
• Direct Digital Synthesis (DDS): DC to 105 MHz output with <0.075 Hz frequency resolution
• Phase-Locked Loop (PLL) for phase-locking to user-supplied CLKIN reference
• Reference clock import/export for flexible timing configuration

Connectors and Interfaces
• CLKIN: AC-coupled, 50 Ω terminated input for external 10 MHz reference with software-controlled attenuation
• CLKOUT: Selectable routing of TCXO, PXI_CLK10, or DDS clock outputs
• Programmable Function Interface (PFI) connectors for general-purpose signal routing

Power
• +3.3 V: 800 mA maximum

– Key Features

Precision clock generation with DDS flexibility enables frequency synthesis across a wide range. The 1 ppm TCXO significantly outperforms standard backplane oscillators for applications requiring measurement accuracy. Low-skew star trigger distribution maintains timing coherence across large chassis configurations. Phase-locking to external references extends synchronization to networked and multichassis deployments.

– Typical Applications

Multichannel data acquisition requiring synchronized sampling. Distributed test systems spanning multiple PXI chassis. External clock synchronization with laboratory instruments and radio frequency equipment. High-accuracy timing in aerospace, communications, and precision measurement systems.

– Compatibility & Integration

Mounts in PXI Express timing slot. Distributes signals to all remaining PXI Express slots via backplane and front-panel connectors. Compatible with external 10 MHz references and capable PXI modules leveraging improved clock accuracy.