The National Instruments AT-232/4 Serial Interface is a robust 4-port serial communication solution designed to connect and control a variety of external serial hardware such as terminals and modems. Manufactured by National Instruments, this device leverages the RS-232 standard to facilitate asynchronous data transfer at rates up to 115.2 kbps. Each port is equipped with registered jacks (RJ45) or 10-position modular phone jacks for seamless connectivity to Data Terminal Equipment (DTE) or Data Communication Equipment (DCE). The AT-232/4 features interrupt sharing capabilities among its ports, ensuring efficient resource management. With a power requirement of 340 mA to 450 mA at 5V, it can be conveniently powered via USB, eliminating the need for external power sources. The design incorporates RTS/CTS hardware-handshake lines to guarantee reliable data transmission integrity. Additionally, the AT-232/4 is compatible with Windows 2000/9x operating systems and includes a FIFO buffer size of 16 bytes to optimize data handling. This unit operates effectively in humidity conditions ranging from 10% to 90%. The AT-232/4 measures 4.2 inches in height and 6.5 inches in depth, and it is backed by a 2-3 year warranty. For further information, user manuals are available for download, and pricing details can be obtained by contacting a sales representative.