Part Number 778289-01 corresponds to the National Instruments BNC-2121 Terminal Block, a crucial module that facilitates connectivity with NI 660x counter devices, enabling comprehensive functional testing. The BNC-2121 features a 68-pin male SCSI-II I/O connector to interface with NI 660x devices, along with 14 BNC connectors and 72 screw terminal plugs for versatile signal connections. Out of the BNC connectors, 8 are designated for PFI lines (32 to 39), while the additional 6 BNC connectors support user-defined fields. The terminal block includes 2 spring terminals specifically designed for quadrature encoders with a resolution of 24 pulses per revolution and a 1µs pulse width output, in addition to a spring terminal for a trigger signal that aids in measurement synchronization.

This module effectively integrates a function generator capable of producing TTL-compatible square waves with frequencies from 10 Hz to 1 MHz, characterized by rise and fall times of 250 ns and 50 ns, respectively. Additionally, it features 8 LED status indicators for each digital I/O line, enhancing usability and monitoring capabilities. The BNC-2121 draws 200 mA of current from the NI 660x at a power supply of 5 VDC (±5%), with the available power at the screw terminals reaching up to 600 mA. Designed to operate in environments ranging from 0 °C to 50 °C with a relative humidity of 10% to 90% RH, the device can be safely stored at temperatures from -20 °C to 70 °C. Compliance with key safety standards, including IEC 61010-1 and UL 3111-1, underscores the suitability of the BNC-2121 for both laboratory and industrial applications. The overall dimensions of the module are 10.69 x 4.41 x 2.05 inches, making it a compact yet powerful addition to any automation framework.