The National Instruments BNC-2090 Rack-Mounted BNC Terminal Block, designated by part number 777270-01, provides efficient connectivity for a variety of data acquisition systems. This terminal block interfaces seamlessly with NI MIO and PC-LPM-16 DAQ boards, making it compatible with numerous personal computers, including IBM PC/XT/AT, Macintosh NuBus, Sun SPARCstation, and NEC PC-9800 Series systems. The BNC-2090 supports 16 analog input channels, configurable in a single-ended mode or a differential mode with 8 channels. It is designed for industrial and laboratory applications, allowing for the connection of both analog and digital signals to data acquisition boards. Additionally, it features silkscreened locations for optional resistors and capacitors for constructing single-pole highpass and lowpass filters or voltage dividers.

The terminal block can be configured using nine front panel switches to select between differential (DIFF), referenced single-ended (RSE), or nonreferenced single-ended (NRSE) modes, accommodating a variety of measurement needs depending on whether the source is floating or ground-referenced. Its physical dimensions measure 19 by 7.4 by 1.7 inches and include two 68-position male connectors for input/output operations, alongside 22 BNC connectors (18 analog, 2 digital, and 2 user-defined) and 28 spring terminal blocks. This device requires a power supply of +5 VDC (±5%) from the host computer, typically consuming 10 mA when no signal conditioning is implemented, up to a maximum of 1 A, which is fuse-limited by the host DAQ board. Operating conditions are specified to range from 0 °C to 70 °C with relative humidity levels between 5% and 90%, while storage conditions allow for temperatures between -55 °C and 125 °C.