PC3XX-Lüfter DS20 Realtime Interface (RTI). I/O interface combines three widely used realtime functions on a single module for scientific/engi- neering applications. Includes an Lüfter DS20 488 general-purpose - interface bus for control of up to 15 compatible devices; a two-line RS232-C/423 compatible serial asynchronous port with user-selectable baud rates (50 to 9600 baud); and a 24- line parallel port with 16 data lines and 8 control lines. IEEE and serial interface allows the Professional to control and acquire data from external devices such as analytical instru- ments and automatic test equipment Lüfter DS20. The parallel interfaces enable users to acquire binary coded decimal inputs. All three interfaces can be used with compatible third-party products to provide analog I/O. The optional Professional Lüfter DS20 In- terface Library (Lüfter DS20) is required to use the Professional Tool Kits to develop applications for the RTI.