National Instruments 779929-01 Timing and Control Module  

National Instruments part number 779929-01 is an identifying part number for the PXI-6682, a PXI Timing and Synchronization Module with One 3U CompactPCI slot, 3 SMB PFI Lines and an Input Frequency Range of DC to 30 MHz. The NI 779929-01 can route clock triggers and signals within a PXI chassis or between multiple chassis with low skew, allowing users to synchronize multiple devices in a single PXI system. The front panel of this module includes a GPS Antenna Connector, a CLKOUT Connector, a CLKIN Connector, a PFI0/IRIG-B Input Connector, an Ethernet Connector, PFI <1..2> Connectors, and LEDs for GPS, 1588, Ethernet Link, and Ethernet speed. 

The CLKIN input for this module operates at a fundamental frequency of 10 MHz, accepting either sine or square waves. It has a nominal input impedance of 50 Ω and AC coupling. The voltage range for CLKIN is from 400 mVp-p to 5 Vp-p, with an absolute maximum input voltage of 6 Vp-p. For synchronous events, this Timing and Control Module uses IEEE 1588, IRIG-B, and GPS to synchronize PXI and PXI Express systems. It can generate clock signals and events at precisely synchronized future times and timestamp input events with the synchronized system time. 

The NI device requires one 3U PXI slot and has a programmable clock ranging from DC to 1.5 MHz. This connector can also receive the RF signal from the attached GPS antenna. This device has three SMB general-purpose PFI lines and uses NI Sync software as its driver. For programming, users can utilize NI application development environments (ADE) such as LabWindows/CVI, LabVIEW, or Visual C/C++. This module is typically installed in slot 2 of the PXI chassis and requires one slot. 

The part number 779929-01 provides full control over the timing and synchronization features of the PXI backplane. To function as a PXI star trigger controller or provide a high-accuracy, free-running 10 MHz reference clock, it must be installed in slot 2 of the PXI chassis. Signals may be routed to and from the PXI star triggers, the PXI triggers, and the front panel. Additionally, you can invert the polarity of the destination signal, which is useful for managing active-low digital signals.