Data transmission/receiving device having parallel/serial and serial parallel character conversion, particularly for data exchange between communicating data processing systems

摘要

In a data transmitting/receiving device having parallel/serial and serial/parallel character conversion, particularly for data exchange between communicating data processing systems, and being arranged between a local data processing system and a data modem terminating a data communication line for the purpose of controlling data transmission and/or reception procedures and containing a procedure store, and in which a random access storage is provided as a data buffer for intercepting data jams is provided along with an interrupt control for interrupting processing operations in a microprocessor in respect of higher processing priority, and in which a timer is provided for setting optimum transmission speed, first and second modem connection lines are provided and data messages to be transmitted are converted bit-oriented or character-oriented by the microprocessor from data groups supplied thereto by means of corresponding input switching commands. In addition, the optional transmission of bit-oriented data messages according to the synchronous data link control (SDLC) method or according to the high- level data link control (HDLC) method is provided.