Michael C Austin

US Patent:

40030326, Jan 11, 1977

Filed:

Jun 9, 1975

Appl. No.:

5/584994

Inventors:

Michael M. Austin - Salt Lake City UT
William G. Barrett - Bountiful UT

Assignee:

Sperry Rand Corporation - New York NY

International Classification:

G06F 300
G06F 304

US Classification:

3401725

Abstract:

A system for and a method of automatically determining the terminal characteristics and line speed of an unknown asynchronous line terminal are disclosed. The automatic terminal and line speed detector (ATLSD) is a feature that is selectably addable to an existing communications multiplexer module (CMM) of an existing communications controller (CC). The CMM provides the means for selectively intercoupling one of a plurality of different line terminals (LT) at a plurality of remote sites to a central processor (CP) at a central site. The ATLSD includes an ATLSD Table in which are stored a plurality of multibit terminal identifier characters (TICs), each of which TICs defines the terminal identity, terminal characteristics and line speed of the LT that is identified thereby. When ATLSD is desired, a command from the CP places the ATLSD in the scan mode and loads a count transition number (CTN) and a character transition number (KTN) into associated registers of the CMM. The first character that is transmitted by the LT that is to be identified by the ATLSD is sampled by a transition detector for Mark to Space and Space to Mark transitions with a real-time sample counter initiated by the first Mark to Space transition caused by the initial Start (S. sub. T) bit.