Alan P Rothlauf

US Patent:

43251471, Apr 13, 1982

Filed:

Jun 16, 1980

Appl. No.:

6/159571

Inventors:

Alan P. Rothlauf - Ypsilanti MI

Assignee:

Minnesota Mining & Manufacturing Co. - St. Paul MN

International Classification:

H04J 300
H04J 400

US Classification:

370 91

Abstract:

An asynchronous multiplex system allows full duplex communication between a plurality of terminals each provided with a universal, asynchronous receiver-transmitter (UART) which serially receives data information from a source thereof and is operative to produce a flag signal indicating that all of the bits of a data word have been received for storage therein and are ready for transmission. The multiplex system includes a transmitter section and receiver section servicing a group of data terminals. The transmission section includes a scanner which sequentially interrogates the UARTS associated with each of the corresponding data terminals, and control logic for causing the data words stored in a UART to be delivered to a transmission shift register for temporary storage. The transmitter section further includes an encoder which develops a data code identifying the particular terminal from which the data word is being transmitted. The control logic causes the data word and corresponding code to be simultaneously transmitted as a single, multi-bit data message over a transmission path to the receiving section of another multiplexer servicing another group of terminals.