Adapter cluster module for data communications subsystem

• US 4,200,930 A
• Filed: 08/10/1978
• Issued: 04/29/1980
• Est. Priority Date: 05/23/1977
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Burroughs Incorporated (Terreno Realty Corp.)
• Inventors: Rawlings, Robert L., Mathews, Ronald D.
• Primary Examiner(s): Springborn, Harvey E.
• Application Number:
  US05/932,698
• Time in Patent Office: 628 Days
• Field of Search: 364/200 MS
• US Class Current: 709/212
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices

Abstract

In a digital data communication network there is provided a data communications subsystem working in conjunction with a main host system having a central host processor and main memory. The data communications subsystem provides a data communications processor and a local autonomous data communications memory connected to a basic control interface unit which supports a plurality of front-end controllers. The data communications subsystem can sense a halt in the main system and operate autonomously and independently of the main host system during such down-time. The present disclosure describes a front-end controller-processor called an adapter cluster module which is used to control a plurality of line adapters, each of which communicates with remote terminals on low to medium speed transmission lines. Up to 16 such adapter cluster modules may be accommodated as front-end controllers within a single data communications subsystem. Each adapter cluster module can handle up to eight transmission lines operating in full duplex mode. A ROM memory area is provided for standard program routines. A RAM memory is provided for storage of special routines and instructions in addition to a scratchpad area for accumulation of a full message block before any interruption is made to the data communications processor requesting further data transfer instructions. Thus, a large magnitude of overhead operations are removed from the data communications processor which formerly was interrupted each time a byte of information was received by the adapter cluster module.

Claims

1. In a data communications network having a plurality of peripheral terminals connected via transmission lines to a central station, wherein said central station includes a main host system having a host processor and main memory, said main host system connecting to a data communications subsystem dedicated to the handling of data transfer operations, said data communications subsystem including a data communications processor, a local autonomous data communications memory and a plurality of front-end controllers including an improved adapter cluster module front-end controller-processor which connects to a plurality of remote peripheral terminals via line adapters, an improved data communications subsystem including said improved adapter cluster module comprising:

(a) a data communications processor connected to said main host system for providing pointer addresses and instructions to be accessed by each of said front-end controllers associated with the data communications subsystem and wherein said data communications processor includes;

(a1) means to sense a halt or failure in said main host system and;

(a2) means to initiate continuous autonomous operation of said data communications subsystem independently of said main host system during any period when said main host system is inoperative;

(b) a plurality of specialized front-end controllers for executing data transfer operations for different speed and line disciplines of transmission lines to peripheral terminals, each of said front-end controllers capable of accessing instructions from addresses in main memory or addresses inlocal autonomous data communications memory, said addresses being provided by said data communications processor;

(c) a basic control interface providing control and communication exchange between;

said data communications processor, said local autonomous data communications memory and said front-end controllers;

(d) a local autonomously operating data communications memory directly accessible to said data communications processor and each of said front-end controllers;

(e) a command block in local data communications memory for providing instructions, control and information data for each individual front-end controller;

(f) an improved adapter cluster module front-end controller-processor including;

(f1) a plurality of line adapters each one of which is connected via transmission lines to a separate remote peripheral terminal, said line adapters being controlled by a central control means;

(f2) a central control means including;

(f2a) ROM memory means for storing data transfer program routines;

(f2b) RAM memory means for temporary storage of data received from remote peripheral terminals or for temporary storage of data ready for transmittal to said remote peripheral terminals, said RAM memory including dedicated storage areas for each specific line adapter connected to a remote terminal, said RAM memory also including memory space for temporary storage of specialized routines as directed by said data communications processor;

(f2c) processing means for processing instructions fetched from said ROM and/or said RAM memory means;

(f2d) a plurality of working registers for the storage of addresses, instructions and data which is to be transmitted and/or processed either to/from said remote peripheral terminals or to/from said data communications memory.

2. The improved data communications subsystem having said improved adapter cluster module of claim 1 wherein said improved adapter cluster module front-end controller-processor further includes:

(g) means in said RAM memory means for the accumulation of eight bytes of data to form a full message block;

(h) means to sense the accumulation of a full message block in said RAM memory means, and to signal an interrupt to said data communications processor only after a full message block has been accumulated.

3. The improved data communications subsystem including said improved adapter cluster module of claim 2 wherein:

said RAM memory means provides temporary storage for specialized programs suitable for newly added non-standard remote terminals and line adapters.

4. The improved data communications subsystem including said improved adapter cluster module of claim 2 wherein said ROM memory means is connected on a plug-in non-fixed basis wherein it may be easily replaced with another programmed ROM memory means having other desired program routines.

5. The improved data communications subsystem including said improved adapter cluster module of claim 2 wherein each of said adapter cluster module front-end controller-processors can control data transfers along eight transmission lines on a full-duplex basis.

6. The improved data communications subsystem including said improved adapter cluster module of claim 2 wherein one data communications processor and one local autonomous data communications memory may control the operations of up to 16 adapter cluster module front-end controller-processors in order to provide full-duplex operation on 128 transmission lines to remote terminals.

7. The improved data communications subsystem of claim 1 wherein said improved adapter cluster module front-end controller-processor includes:

(i) means to sense specialized control characters indicating the end of a transmitted text before any interrupt signal is sent to said data communications processor.

8. The improved data communications subsystem including said improved adapter cluster module of claim 1 wherein each of said plurality of line adapters includes:

(f1a) adapter control circuitry for the input of information-data from said data communications memory via said central control means and an output bus for the output of data received from a remote terminal associated with each of said line adapters;

(f1b) a cyclic redundancy checker for detecting errors in any bit of data received from said remote terminal;

(f1c) an interface connecting each of said line adapters to a telephone data set.

9. The improved data communications subsystem including said improved adapter cluster module of claim 1 wherein said adapter cluster module front-end controller-processor further includes:

(g) an adapter service unit connected to said plurality of line adapters, said adapter service unit including;

(g1) scan selection means connected to said central control means for selecting a particular adapter to be serviced;

(g2) gating logic means for connecting any selected line adapter to said central control means;

(g3) a micro-control processor connected to;

said central control means, said gating logic means, and to a realtime clock for regulating the serial bit flow-rate in the transfer of data to and from the said remote terminal;

(g4) a holding register for buffering data transfers to/from said remote terminals;

(g5) a real-time clock for providing designated baud rate timing periods for each of said line adapters.

10. In a data communications subsystem connected as an operating part of a main host computer system having a central processor and main memory, and wherein said data communications subsystem includes a data communications processor and a local autonomous data communications memory both connected through a common interface to a plurality of frontend controllers which are controlled by said data communications processor wherein said data communications subsystem can operate autonomously and independently of the main system during any period when the main system is halted, an improved front-end controller designated as an adapter cluster module for relieving the overhead operations which would normally be required of the said data communications processor during data transfer operations between said adapter cluster module and a plurality of remote peripheral terminals connected thereto on low/medium speed transmission lines, said adapter cluster module comprising:

(a) a plurality of line adapters, each line adapter connected via a dedicated transmission line to a separate remote peripheral terminal, each of said line adapters including;

(a1) adapter control circuitry for the input of information data from a data communications memory via a central control unit, and an output bus for the output of data received from an associated remote terminal;

(a2) a cyclic redundancy checker for correcting bits of data received from said remote terminal;

(a3) an interface connecting said line adapter to a telephone data set;

(b) an adapter service unit connected to said plurality of line adapters, said adapter service unit including;

(b1) scan selection means connected to a central control means for selecting a particular adapter to be serviced;

(b2) gating logic means for connecting any selected line adapter to a central control means;

(b3) a micro-control processor connected to;

said central control means, to said gating logic, to said adapter control circuitry and to a real-time clock for regulating the serial bit flow in the transfer of data between the remote terminal, its line adapter and a holding register in said adapter service unit;

(b4) a holding register for buffering data transfer to/from remote terminals;

(b5) a real-time clock for providing designated baud rate timing periods for each of said line adapters;

(c) a central control means connected to said adapter service unit and having interfaces to said data communications memory and said data communications processor, said central control means including;

(c1) ROM memory means for storage of data-transfer routines;

(c2) RAM memory means for temporary storage of specialized data transfer routines received from said data communications memory at the direction of said data communications processor and for providing dedicated storage space for each line adapter and its associated remote terminal;

(c3) means to send an interrupt signal to said data communications processor only upon accumulation of a message length block of data in said RAM memory means;

(c4) means to select instructions from said ROM memory means and/or said RAM memory means for data transfer operations;

(c5) instruction register means to hold instructions fetched from said ROM memory means and/or said RAM memory means for execution of data transfer operations;

(c6) a plurality of working registers for temporary storage of the address of line adapters to be selected for data transfer operations and for storing addresses of information in data communications memory, and for temporary storage of data words;

(c7) processing means for execution of data transfer instructions and/or word processing instructions residing in said instructions register.

11. The adapter cluster module of claim 10 wherein each of said line adapters can be controlled for data transfers on full duplex operation.

12. The adapter cluster module of claim 10 including means to control at least eight line adapters.

13. The adapter cluster module of claim 10 wherein said RAM memory means includes storage area for any special non-standard program routines required to control non-standard remote terminals, such said special program routines being loaded therein by said data communications processor.

14. In a data communications system having a main computer including a main host processor and main host memory and working in conjunction with a data communications subsystem having its own power source, which subsystem includes at least one data communications processor which controls one or more front-end controllers used to manage data transfer operations to and from remote peripheral terminal units, the data communications subsystem comprising:

(a) a local autonomous data communications memory for storage of instructions, control data, and for storage of information data, said data communications memory dedicated for independent operation of said data communications subsystem, said data communications memory being directly accessible by an associated data communications processor and associated group of front-end controllers;

(b) a basic control interface for connecting a group of front-end controllers to said local autonomous data communications memory and to said data communications processor;

(c) a plurality of front-end controllers, each of said front-end controllers dedicated to a particular type of data communications and data transfer operations, each of said front-end controllers having processing means for controlling data transfer operations between connected peripheral terminals and the autonomous data communications memory and the main host memory;

(d) a data communications processor for initializing, starting, and stopping said plurality of front-end controllers, said data communications processor including;

(d1) means for providing an address pointer to each front-end controller to permit each front-end controller to access data transfer commands and routines from the autonomous data communications memory or from the main memory;

(d2) means to sense a halt of the main host system and to place the data communications subsystem on an autonomous operating basis independent of the halt in the main host system;

(d3) means to sense normal operation of the main host system and to resume normal intercommunicating relationships between the main host system and the data communications subsystem;

(e) a front-end controller designated as an adapter cluster module constituting at least one of said plurality of front-end controllers, said adapter cluster module including;

(e1) a plurality of line adapters, each of which has a dedicated transmission line to a remote terminal;

(e2) a central control means connected to said line adapters wherein said central control means includes;

(e2a) ROM memory means for storing program routines;

(e2b) processing means for executing data transfer instructions;

(e2c) RAM memory means for receiving and storing specialized data transfer routines from said data communications processor and for temporary storing of data in areas dedicated to each one of said line adapters;

(e2d) working register means for storage of addresses of a line adapter to be serviced and for storage of data communications memory addresses to be accessed, and for storage of data to be transferred or processed;

(e2e) connection means to said data communications processor;

(e2f) connection means to said data communications memory;

wherein said adapter cluster module controls all data transfer operations, editing, and translation with respect to data being transferred between said remote peripheral terminals and said data communications memory and wherein said adapter cluster module does not interrupt said data communications processor except when a complete message block of data has been accumulated and is ready for transfer to said data communications memory.

15. The data communications subsystem of claim 14 wherein at least 16 adapter cluster module controllers can be controlled by one data communications processor in one data communications subsystem to provide 128 transmission lines to remote terminals, each transmission line operating in full duplex mode.

16. The data communications subsystem of claim 14 wherein at least 16 adapter cluster module controllers can be controlled by one data communication processor in one data communications subsystem to provide 128 simplex-transmit lines and 128 simplex-receive lines to remote terminals.