The National Instruments PXI-6652 is a precision PXI Timing and Multi-Chassis Synchronization Module designed for high-resolution clock generation and synchronization across PXI systems. Featuring a frequency resolution of 711 nHz and a clock generation range from DC to 105 MHz, the PXI-6652 enables the import and export of triggers within the PXI backplane and drives start trigger lines effectively. This module generates a temperature-compensated crystal oscillator (TCXO) 10 MHz reference clock, enhancing instrumentation stability to an impressive accuracy of 1 ppm when used in conjunction with PXI chassis.

Occupying a single 3U PXI slot, the PXI-6652 includes a 50 Ω SMB male front panel connector for easy integration. It incorporates a Clock Input (CLKIN) connector to receive external clock signals, which can be routed programmatically to the onboard phase-locked loop (PLL) or distributed directly to the backplane. Additionally, the Clock Output (CLKOUT) connector allows users to select various clock sources for signal distribution, including output from the TCXO, backplane clock, direct digital synthesis (DDS), or oven-controlled crystal oscillator (OCXO).

The module also features six Programmable Function Interfaces (PFI), enabling input or output configuration tailored to specific synchronization requirements, including the use of PFI 0 as a clock input for internal signal synchronization. Controlled via the NI-Sync driver software, the PXI-6652 supports programming through multiple application development environments, including LabVIEW, LabWindows/CVI, and Microsoft Visual C++. The module has dimensions of 3.9 x 6.3 inches and is rated for operating temperatures between 0 to 55 °C, with a storage temperature range of -20 to 70 °C. While classified as obsolete, the PXI-6652 remains available through Apex Waves, ensuring continued accessibility for various industrial automation needs.