The 59403A HP-IB/Common Carrier Interface provides a way to extend the separation of component parts in an HP-IB system by more than the 20 meter maximum transmission path length specified in various interface standards, and it's especially useful for production or remote site applications. Converts HP-IB data and control lines to a serial bit stream of digital information to transmit up to 1000 meters. Operates with 110 baud, 300 baud, or 1200 baud asynchronous full duplex modems which are EIA RS232C or CCITTV24 compatible