The National Instruments 781157-01 USB CompactDAQ Chassis is a versatile four-slot chassis designed to serve as a central component in portable sensor measurement systems. Part of the cDAQ-9174 model range, this chassis features a plug-and-play USB interface for streamlined connection to C Series I/O modules, facilitating a range of measurement tasks including analog input/output, digital I/O, and counter/timer operations. It enhances measurement accuracy with its four 32-bit general-purpose counters/timers and supports up to seven simultaneous hardware-timed processes. The chassis features improved timing capabilities through three separate analog input rates and ensures robust communication with the host computer via two status LEDs indicating operational readiness—READY and ACTIVE.

Equipped with a Hi-Speed USB 2.0 interface, the 781157-01 ensures effective data transfer while a locking mechanism mitigates strain on the USB cable. The device supports autodetection, signal routing, synchronization, and manages data flows between the STC3 timing engine and C Series modules. The STC3 is capable of triggering, supporter of PFI signals for synchronization across devices, and can offer high-speed data streams with adjustable sample timing.

Analog input functionality provides a FIFO size of 127 samples per slot and allows for variable sample rates determined by the connected C Series modules, maintaining a timing accuracy of 50 ppm and a resolution of 12.5 ns. The chassis supports hardware-timed analog outputs for up to 16 channels with a maximum update rate of 1.6 MS/s. Additionally, users can create digital waveforms and adjust clock frequencies according to application requirements. Digital triggers from any module PFI terminal allow for flexible signal polarity selection through software, enhancing control over measurement processes involving analog input/output and counter/timer functionalities.

With its robust feature set and adaptability, the National Instruments 781157-01 is an integral solution for comprehensive sensor measurement applications.