The National Instruments part number 781496-01 refers to the cDAQ-9181 CompactDAQ Ethernet Chassis, designed for integration with NI's Compact series I/O modules and controllers. This streamlined chassis features a single slot capable of accommodating various modules while providing connectivity through an RJ-45 Ethernet port that supports speeds from 10 to 100 Mbps. It employs TCP/IP and UDP network protocols, facilitating six high-performance data streams with a default maximum transmission unit (MTU) size of 1500 bytes. To monitor operational status, the chassis is equipped with LED indicators that display the state of the Ethernet network and any connected modules or controllers.

Offering an Analog input FIFO size of 127 samples, the cDAQ-9181 ensures a timing accuracy of 50 parts per million (ppm), with rates determined by the attached C series module. Additionally, it includes four 32-bit timers or counters for precise clock signals and time-related measurements, as well as a frequency generator capable of three base clock frequencies: 20 MHz, 10 MHz, and 100 kHz. The chassis' compact design, measuring 88.1 mm x 88.1 mm x 44.1 mm (3.47 in. x 3.47 in. x 1.74 in.), is constructed from lightweight aluminum, making it portable and suitable for desktop or DIN rail mounting. For secure installation in industrial environments, an optional NI 9903 panel mount kit and NI 9913 DIN rail kit are available.

The cDAQ-9181 chassis operates from a power supply input ranging from 9 VDC to 30 VDC and is designed to function effectively within an operating temperature range of 0 °C to 55 °C, as it lacks an onboard cooling fan. Furthermore, it has an Ingress Protection (IP) rating of IP30, safeguarding against entry of solid objects larger than 2.5 millimeters, though it is not liquid-proof. The lightweight unit weighs 238 g (8.4 oz), making it an efficient solution for compact automation requirements.