IES59857B2 - A communication system - Google Patents

Description

A Communication System The invention relates to a communication system for the processing, transmission, receipt and outputting of data in real-time.

British Patent Specification No. GB-B-2,153,118 (N.V.

Philips) describes a system having a number of data processors which are interconnected by a communication network. The system comprises a set of stations which are all interconnected by a general communication network, each station having a set of processors and a memory and being capable of executing a set of superprocesses. The system provides the feature whereby different superprocesses can communicate better at the level of a block, while communication between processes of a single superprocess usually takes place at the level of a memory access, for example, on a word basis. While such features are undoubtedly of benefit, there are some communication requirements to which this system does not apply. One such requirement is where there is a host computer which must refer to large databanks and to other processors for carrying out the processes associated with communications. Such a host processor is typically connected to a set of slave terminals which do not have distributed processing capacities. Accordingly, it is essential that the host computer carry out the data processing and must process data and direct transmission and reception of data. Where a host computer is required to carry out the data processing and to activate communication sessions on a real-time basis, there is either a long response period to a data request, or alternatively an extremely powerful computer installation which is both very expensive to L install and to maintain as required.

S598S7 The invention is directed towards providing a communication system which incorporates a host computer which carries out general data processing operations, and in addition data processing associated with 5 communications, and also directs the communications so that data is retrieved and outputted back to the user interface in real-time.

According to the invention, there is provided a communications system comprising :10 a host computer comprising :a build processor; a receive processor; a mapped structure; non-volatile outgoing memory a counter; and a mapped non-volatile incoming memory structure, a communications controller connected for bidirectional communication with the host computer 20 and comprising:pre-mapped sections of memory for incoming and outgoing data; remote communication ports; means for directing operation of a modulation device; and a processor comprising means for controlling ., the remote communication ports and for accessing data stored on the host computer; r wherein the build processor comprises means for monitoring a random access memory of the host computer for detection of a data request signal received from a slave terminal, means for writing a flag to a queue stored in a non-volatile memory, means for stripping the data request into a header and detailed information and writing the header information to a header file and the detailed information to a detail file, both stored in nonvolatile memory; wherein the build processor also comprises means for operating in parallel to said means for monitoring the random access memory to automatically monitor write instructions of flags to the data request queue, means for automatically creating a trigger file in a portion of nonvolatile memory accessible by the communications controller, there being one trigger file for each data request flag in the queue, means for building a transfer package in response to detection of a data request flag, and means for incrementing the counter when the transfer package has been built, wherein the communications controller comprises a means for accessing the non-volatile memory of the host computer to detect presence of a trigger file and for automatically retrieving the associated C transfer package and transmitting said package to a remote database; wherein the communications controller comprises means for monitoring reply signals from the remote database and for automatically writing received v data to the incoming memory structure of the host computer; wherein the receive processor of the host computer comprises means for automatically monitoring the incoming memory structure for detection of data written by the communications controller, for 10 detecting if automatic printing is required, and for activating a print controller to direct printing of the received data.

In one embodiment, the communications controller comprises means for automatically generating a wait file and storing 15 said file in the outgoing memory structure of the host processor upon detection of a trigger file, and the build processor of the host computer comprises means for automatically renaming the wait file when the counter value precedes a pre-set value to provide a transfer file.

Preferably, said pre-set value is set by a parameter file accessed by the build processor at the beginning of the communications session.

In one embodiment, the transfer file is automatically detected by the communications controller and information 25 in said file is used for retrieval of a relevant transfer package, and the communications controller comprises means - for transmitting said package to the remote database. λ In another embodiment, the communications controller comprises means for interactively communicating with the 30 remote database for retrieval of data.

In a still further embodiment, the receive processor comprises means for monitoring the incoming memory structure and for automatically creating a list file containing address information for each set of received ir data stored in the incoming structure.

In this latter embodiment, the receive processor comprises means for operating in parallel to monitor the list file and to generate receive header and detail files, the receive header file containing all of the data stored in the request header file for that particular data request.

Ideally, the receive processor comprises means for automatically updating the request header with event notifications including a time stamp.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings in which : Fig. 1 is a diagram showing a communications system of the invention; Fig. 2 is a diagram showing data and signal flows during operation of the system; Fig. 3 is a flow chart showing operations of both a host computer and a communications controller; and Fig. 4 is a diagram showing operations of the host rcomputer for processing data being received from a remote source.

Referring to the drawings, and initially to Fig. 1, there is shown a communications system of the invention, indicated generally by the reference numeral 1. The system 1 comprises a host computer 2. The host computer 2 is connected to a communications controller 3 which is a microcomputer configured with the necessary communication circuits and software programs to direct communications with a remote system. A set of slave terminals 4 are connected to the host computer 2 and these are connected by various communication media including dial-up, leased line, and X 25 network communication 10 links. The construction of the host computer 2 and of the communications controller 3 is described in more detail below. However, because of their importance, two major memory structures within the communications controller 3 are illustrated in Fig. 1 and these are an outgoing memory 15 structure 5(a) which is used in generation of data requests, and an incoming memory structure 5(b) which is used in the processing of incoming data. The communications controller 3 is connected to a 9600 baud modem 6 which is connected to a database link 7 which in 20 this embodiment is a leased line.

Very briefly, the function of the communications system 1 is to carry out data processing in response to data requests received from a slave terminal 4. The system 1 then transmits instructions and data to the remote 25 database via the link 7 and subsequently receives a response, which response is then processed in order to provide output data. The invention provides technical features within the system 1 to provide for fast response times.

Reference is now made to Figs. 2 to 4. When a user inputs a data request at a slave terminal 4, a build processor 13 forming part of the host computer 2 is automatically activated and it retrieves from disk a parameter file and reads parameter values from the file in working memory.

The data request is stored in a random access memory (RAM) 10 and information or data within the request is divided into two categories by the build processor 13, namely a header category and a detailed data category. The header data is written to a header file 11(a) and the detailed data is written to a detailed data file 11(b). The build processor 13 also directs writing of a new flag to a data request queue 12 stored on disk.

Referring additionally to Fig. 3, the build processor monitors the request queue 12 in step 33 to detect a data request flag. If such a flag exists, in step 35 the build processor 13 determines if there is an associated trigger file 17 in existence for the data request, and if not, it creates a new trigger file 17 as indicated by step 36. In step 37, the build processor builds a transfer package 16 in ASCII format. Building of the transfer package is an extremely important aspect as it involves generation of the communication commands and the necessary data for the interrogation of a remote database to retrieve data. The build processor 13 automatically builds the transfer package in response to detection of a fresh data request within the queue 12. In step 38, the transfer package is written to the outgoing memory structure 5(a) and in step 39, the build processor 13 increments by one a counter 14. All of these operations are carried out in sequence by the build processor 13 according to parameter values retrieved from the parameter file at the beginning of each communication session. An important aspect is the fact that the build processor 13 is connected to the data queue 13 and continuously monitors the queue for writing of new data request flags. Immediately upon detection of a new flag, it proceeds to build the transfer package, write a 5 trigger file if one does not already exist, and to increment the counter 14. In almost all cases, it will be necessary to create a new trigger file as it is quite seldom that an auxiliary processor will insert a trigger « file relating to a data request. i In step 40, the build processor 13 reads the value in the counter 14 and if five or less, it repeats the above5 described steps to build a new transfer package for a new data request. When the count exceeds 5, the build processor 13 monitors a pre-defined section of the outgoing memory structure 5(a) for detection of a file called a wait file. It is now appropriate to refer to 10 the flow charts 31 and 32 which describe some of the operations of the communications controller 3. In the flow chart 31, the communications controller 3 polls the outgoing memory structure 5(a) for detection of a trigger file 17. The trigger files are so named because they are 15 used for activating the communications controller 3. As indicated by the decision step 43, the communications controller continues to poll the outgoing memory structure 5(a) until a trigger file 17 is detected. When a new trigger file is detected, as indicated by step 44, the 20 communications controller 3 creates a wait file and writes it to the outgoing memory structure of the host computer 2. It is this wait file which the build processor 13 attempts to detect in step 41 and when it detects such a file, the processor 13 automatically 25 renames the wait file as a transfer file in step 42.

Again, the transfer file is stored in the outgoing memory structure 5(a). This is an important aspect as all of the processors both in the communications controller 3 and in the host computer 2 refer to pre-mapped memory locations ·, 30 within the outgoing memory structure 5(a). 1 It is now appropriate to refer to the flow chart 32 which also describes operation of the communications controller 3. While the communications controller 3 polls the outgoing memory structure 5(a) of the host computer 2, it also attempts to detect a transfer file as indicated by the step 45 and again, polling is repeated until such a .. transfer file is detected. As indicated by the step 46, the communications controller 3 immediately upon detection V of a transfer file copies all packages stored in the relevant portion of the outgoing memory structure 5(a) to a non-volatile memory, namely, a disk of the communications controller 3.

It will be appreciated that by communication between the host computer build processor 13 and the communications controller 3 in this manner, there is very little processing requirement of the host computer 2 and there is almost immediate activation of a communication session with the communications controller 3.

The communications controller 3 then transmits the transfer package to the remote database via the link 7 and automatically logs onto the database machine as a direct user. If the controller 3 needs to log onto the remote machine, it creates an error message which is written to the outgoing memory structure 5(a) of the host computer 2. A function of the build processor 13 is to monitor detection of such an error message and if it is detected, the build processor 13 writes the error message to the header file 11(a) of the appropriate data request. An important feature is the fact that the build processor 13 automatically writes the actual time to the header in the header file 11(a) whenever a write takes place. The communications controller 3 interactively communicates with the remote database machine to request transfer of »data retrieved from the database to a work directory area of the remote machine. Immediately when data is detected 9 in the work area, the communications controller 3 directs transmission of the data back through the link 7 to an appropriate directory structure on its disk. The communications controller 3 repeatably monitors this area of the disk to detect incoming data and automatically writes the data to the incoming memory structure 5(b) of the host computer 2. Immediately when data is written to 5 the incoming memory structure 5(b), a receive processor in the host computer 2 is automatically activated and carries out the operations illustrated in Fig. 4.

As indicated by step 51 of Fig. 4, the receive processor repeatedly monitors the incoming memory structure 5(b) for 10 detection of received data. When received data is detected, the receive processor automatically strips out header information and writes the header information in step 52 to a list file stored on the structure 5(b). The list file simply contains basic memory address and header 15 information for all of the received data.

In a separate, parallel operation, the receive processor reads the list file in step 53 and uses the list file to address data stored in the incoming memory structure 5(b) and writes all of this data to two separate receive files, 20 namely a receive detail file 55 and a receive header file 56. These are analogous to the request files 11(a) and 11(b). An important feature, however, is the fact that the same header data is written to the header 56 as is originally written to the request header file 11(a).

There is thus a one-to-one relationship between the request and receive header files. Generation of the files 55 and 56 is written as an event notifier to the request header 11(a) with the date and time stamp included. This is indicated in step 57 and in step 58, the receive processor monitors the receive header file 56 to determine if the data has been flagged for automatic printing. This flag will also be written to the request header file 11(a) and this file may alternatively be used. If such a flag exists, the receive processor writes a unique code to a print data queue in step 59.

A print controller, not shown, automatically reads the print data queue and directs printing in response to detection of new entries in the queue. It is constructed to automatically refer to the request header and detail files so that the request data and the receive data are merged to provide the printing commands. The steps of accessing the receive files and updating the request header are indicated by the numerals 61 and 62 in Fig. 4, and in step 63 the print controller decomposes the data to provide the correct printing command signals. In step 64 the necessary report is printed. Again, an event notifier is written to the request header file 11(a). These operations are all repeated as indicated by the decision step 60 for each header within the list file which is generated by the steps 51 and 52. It will thus be appreciated that by different portions of the receive processor operating to generate the list file and to act in response to the list file, printing is carried out very quickly using all of the necessary data both inputted by the user and retrieved from the remote database.

It will be appreciated that the invention provides for the synchronisation of different circuits or processors within different data processing machines to provide for a very fast response when a data request is made by a user at a slave terminal 4. This response time is achieved without the need to provide extremely expensive dedicated communication systems and in addition, the data being transmitted and received is integrated with the normal data processing operations of the host computer 2. This is very important for dissemination of data to various memory structures to provide reporting and further data processing, where necessary.

The invention is not limited to the hereinbefore described, but may be varied in and detail. embodiments construction

Claims (5)

1.

A communications system comprising :a host computer comprising :a build processor; a receive processor; a mapped non-volatile outgoing memory structure; a counter; and a mapped non-volatile incoming memory structure, a communications controller connected for bidirectional communication with the host computer and comprising:pre-mapped sections of memory for incoming and outgoing data; remote communication ports; means for directing operation of a modulation device; and a processor comprising means for controlling the remote communication ports and for accessing data stored on the host computer; wherein the build processor comprises means for monitoring a random access memory of the host Λ computer for detection of a data request signal received from a slave terminal, means for writing a flag to a queue stored in a non-volatile memory, means for stripping the data request into a header and detailed information and writing the header information to a header file and the detailed information to a detail file, both stored in nonvolatile memory; wherein the build processor also comprises means for operating in parallel to said means for monitoring the random access memory to automatically monitor write instructions of flags to the data request queue, means for automatically creating a trigger file in a portion of nonvolatile memory accessible by the communications controller, there being one trigger file for each data request flag in the queue, means for building a transfer package in response to detection of a data request flag, and means for incrementing the counter when the transfer package has been built, wherein the communications controller comprises a means for accessing the non-volatile memory of the host computer to detect presence of a trigger file and for automatically retrieving the associated 25 transfer package and transmitting said package to a remote database; wherein the communications controller comprises means for monitoring reply signals from the remote database and for automatically writing received data to the incoming memory structure of the host computer; < 30 wherein the receive processor of the host computer comprises means for automatically monitoring the incoming memory structure for detection of data written by the communications controller, for i detecting if automatic printing is required, and for activating a print controller to direct printing of the received data. 2. A system as claimed in claim 1, wherein the communications controller comprises means for automatically generating a wait file and storing said file in the outgoing memory structure of the host processor upon detection of a trigger file, and the build processor of the host computer comprises means for automatically renaming the wait file when the counter value precedes a preset value to provide a transfer file, and preferably wherein said pre-set value is set by a parameter file accessed by the build processor at the beginning of the communications session, and most preferably wherein the transfer file is automatically detected by the communications controller and information in said file is used for retrieval of a relevant transfer package, and the communications controller comprises means for transmitting said package to the remote database.

3. A system as claimed in any preceding claim, wherein the communications controller comprises means for interactively communicating with the remote database for retrieval of data.

4. A system as claimed in any preceding claim, wherein the receive processor comprises means for monitoring the incoming memory structure and for automatically creating a list file containing address information for each set of received data stored in the incoming structure, and preferably wherein the receive processor comprises means for operating in parallel to monitor the list file and 5 to generate receive header and detail files, the receive header file containing all of the data stored in the request header file for that particular data request, and preferably wherein the receive processor comprises means for 10 automatically updating the request header with event notifications including a time stamp.

5. A system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .