International Business Machines Corporation

Yves Granger

Jean L Calvignac

Daniel Wind

Christian Garcia

Mohamed Badaoui

Richard Dambricourt

Sylvie Spalmacin-Roma

Andre Masclet

Jean-Paul Franquenouille

A scanning protocol is provided for the scanning of a plurality of serial transmission lines connecting users' devices to the scanning means of a communication device, said lines being coupled to the scanning means through line interface couplers (LICs) having each a wired address (n,n', . . . ) known to the scanning means. This scanning protocol requires that for each LIC configuration, a given LICn having a wired address n be re-addressable with a logical address n' corresponding to the wired address of any other active LICn'. This is done in order to determine, for said LIC configuration, the shortest possible scanning scheme including all the active LICs. The re-addressing of a LICn of wired address n, with a logical address n', includes the steps of: resetting the LICn to be affected a logical address n'; setting the logical address n' into LICn; locking said logical address n' into said LICn, and enabling the lines (26) connected to LICn re-addressed with logical address n'.

Protocol and apparatus for selectively scanning a plurality of lines

A line-adapter of a communications controller includes, for scanning the teleprocessing lines connected to it, cyclic scanning means FES exchanging information with the lines through a serial bidirectional link on which data and control informations are partitioned into frames and slots. Since both the FES and the serial link work with their own timings, an interface FESA is provided to adapt the FES scanning to the serial link structure. This FESA includes temporary storage means for storing on the one hand, data and control information transmitted from the LICs to the FES (10) through the inbound serial link, and on the other hand, data and control information transmitted from the FES to the LICs through the outbound serial link. The access of the FES, the outbound and inbound serial link to the storage means is time-shared and granted by an arbitration logic, according to the relative priorities of operation of said elements within the line-adapter of the communications controller.

Scanner interface for the line adapters of a communication controller

The address generating device is provided for a communication line scanning device. The lines are connected to the scanning device through n line interface circuits, n varying in accordance with the network configuration. Each interface circuit can be connected to a various number of lines, for instance one line or k lines in a preferred embodiment, and comprises means for providing to the address generating device, a presence indicating signal indicating that it is plugged and a signal indicating the number of the lines connected thereto. A first logic circuit receives the presence indicating signals as inputs and generates on its outputs the address bits of the last present interface circuit to be scanned. A first counter able to count in binary mode up to n-1 is incremented by an increment pulse provided by a clock on each period assigned to the scanning of a line. This counter outputs the address bits of the successive interface circuits. A comparator compares the address bits so generated and the address bits of the last present interface circuit to be scanned and outputs a reset signal when these bits are equal.

Address generating device for a communication line scanning device

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Antibes, France

Yves Granger