Browse Prior Art Database

Serial Link Architecture Allowing to Attach a Plurality of Tributary Equipments to a Centralized Device Through Only Two Twisted Wire Pairs

IP.com Disclosure Number: IPCOM000035784D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 55K

Publishing Venue

IBM

Related People

Granger, Y: AUTHOR [+3]

Abstract

Disclosed is a serial link for transmitting control and data information, in full-duplex time-shared mode.

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Serial Link Architecture Allowing to Attach a Plurality of Tributary Equipments to a Centralized Device Through Only Two Twisted Wire Pairs

Disclosed is a serial link for transmitting control and data information, in full- duplex time-shared mode.

In both directions, the serial information is spread over contiguous FRAMES: Inside each FRAME, 2 eight-bit slots are dedicated to

each attached equipment, one slot for data exchange,

one slot to pass control information.

A SUPERFRAME is a sequence of 32 FRAMES, used to

exchange typically up to 32 different pieces of control

information with 32 pieces of attached equipment.

A given FRAME transfers the same kind of control information for all 32 pieces of equipment.

Fig. 1 shows an example of FRAME assignation in a communications controller application, where a centralized scanner controls 32 TP lines: in this SUPERFRAME organization, all even frames are devoted to modem control information, and odd frames are used to write or read the registers of the 32 line interface equipment. FRAME 1 is used to write or read register A. Fig. 2 shows that the 32 line interface equipment is implemented in 8 LINE interface couplers (LICs) of 4 lines each.

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The data slot contents (Data Burst) do not depend on the frame number. Depending on the data traffic, the data burst can vary from 0 to 5 bits.

To simplify the hardware at the line level, the data slot organization is not the same in both ways (Rcv and Xmit) (Fig. 3):...