GB2273803A - Multiplexed communication with record-format conversion - Google Patents

Abstract

A method of multiplex communication control and a multiplex communication controller 6 allow improvement of processing efficiency and effective use of CPU resources when multiple communication lines TL1 - TL3 are connected via the controller to a computer 1 such as a personal computer (PC) or workstation (WS). Data records which are transmitted and received through the communication lines in respective formats are collected by the controller, and are converted to or from a common record format which the computer uses. This reduces load on the CPU and the operating system and loss time due to communication control instructions and stand-by time occurring when multiple communication sessions are simultaneously maintained by a single computer. <IMAGE>

Description

MULTIPLEX COMMUNICATION CONTROL METHOD FOR COMPUTERS AND MULTIPLEX COMMUNICATION CONTROLLER FIELD OF THE INVENTION This invention relates to a multiplex communication control method for use when computers such as personal computers or workstations utilized in industry maintain multiple on-line communication lines, and to a multiplex communication controller connected to computers, and more particularly, to reduction in load of instruction processing for communication line maintenance occurring in the operating systems (hereinafter referred to as "OS") of computers and to improvement of the efficiency of data processing in the computer.

DESCRIPTION OF THE PRIOR ART The main object of conventional on-line terminals has been simple tasks such as data entry, correction, deletion, and reference, that is, making use of data and databases present on the host side at terminals (hereinafter referred to as "access").

On the other hand, the main object of personal computers (hereinafter referred to as "PC") or workstations (hereinafter referred to as "WS") has been to use them as stand-alone systems on which to run specific software.

In recent years, due to advances in both hardware and software, PCs and WSs have enabled flexibility in the use of communi cation functions such as the following, by providing, as shown in Figs. 2 and 3, for example, emulator hardware sections 2a to 2c and modems 3a to 3c corresponding to respective communication lines TL1 to TL3 connected to the multiple opposite communication parties Al to A3, connecting them to a PC or WS (hereinafter referred to as "PC (WS)") via interface boards 4a to 4c mounted in the rear slots, and installing emulator software sections 5a to 5c corresponding to respective emulator hardware sections 2a to 2c in addition to the OS in the memory space la of PC (WS) 1.

(1) Using a PC (WS) as a terminal of a host computer via emulator hardware and emulator software.

(2) Accessing programs and data in another PC (WS) by the use of local area networking (hereinafter referred to as "LAN").

(3) Performing data communication between remote PCs (WSs) by use of a modem.

(4) Accessing external databases which are publicly available by information providers.

With these conventional techniques, however, load on the CPU and on the OS due to instruction processing for communication line maintenance are so large that it is difficult, in the light of processing efficiency, to maintain multiple communication lines simultaneously.

In addition, since emulator hardware sections 2a to 2c and emulator software sections 5a to 5c necessary for connection to communication lines TL1 to TL3 have closed structures, it is difficult, technically speaking, to make use of data on an emulator in another application software running on PC (WS) 1 at the same time as the emulator.

More specifically, let us suppose Number of CPU instructions in a given period of time: M Number of CPU instructions in a given period of time for system maintenance: m Number of CPU instructions in a given period of time for synchronous communication for on-line maintenance: T Number of on-line lines connected to the system: N Number of CPU instructions for one data communication during data transmission/reception: C Number of data communications: n then the number of CPU instructions X1 available to users when communication sessions for multiple lines are maintained is theoretically given by X1 = M - m - N*T ... (1) A current industrial demand is to increase the number of lines to improve the availability of PC (WS) 1 and to use high speed communication to accommodate the increasing amount of information.Inferring from the above model, however, problems such as the following arise: (a) As the number of lines is increased, N is increased and the number of instructions X1 available to users is decreased.

Consequently, increasing the number of on-line lines to improve the availability of the PC (WS) 1 causes X1 to decrease, thus lowering the processing efficiency of the PC (WS) 1 at the user side.

(b) If high speed communication is used, T is increased and X1 is decreased.

Consequently, speeding up communication to accommodate the increasing amount of information and the speeding up of information collection causes X1 to decrease, lowering the processing efficiency of the PC (WS) 1 at the user side.

The above two problems are general ones to be solved when promoting the advancement of information across the entire spectrum of industry today.

In contrast to the number of CPU instructions Xl available to users when communication sessions for multiple lines are maintained, the number of CPU instructions X2 available to users when the system performs data transmission/reception is theoretically given by X2 = M - m - N*T - n*C = X1 - n*C ... {2) In this state model, if external data transmission/reception is performed repeatedly in small amounts, n is maximized and X2 is minimized. This is a significant problem in industry when information systems, especially, on-line market information systems such as Reuter's and Telerate are used.

In addition, in model X2 in expression (2) above, if an attempt is made to speed up the processing of the CPU to increase the number of CPU instructions M in a given period of time, because said number of CPU instructions M in a given period of time is determined by the CPU and the OS, speeding up the CPU is, with the prior art, associated with an increase in main memory.

An increase in main memory results in a corresponding increase in the number of CPU instructions m for system maintenance in arith kinetic progression.

Consequently, even if the processing of the CPU is speeded up to increase the number of CPU instructions M in a given period of time to MH, the number of CPU instructions m for system maintenance is also increased to mH.

Supposing MH = aM and mH = ssm, then the number of CPU instructions X3 available to users is given by X3 = aM - ssm - N*T - n*C ... (3) Thus, X3 - X2 = (a - 1)M - (ss - l)m ... (4) Consequently, if an "increase in M" is accompanied by an increase in the OS", the number of CPU instructions m for system maintenance is increased, and therefore, this does not contribute greatly to increasing "the number of CPU instructions X3 available to users In industry, such increase from X2 to X3 has been implemented in the form of "hardware updates" and "OS upgrades". The increase in the number of CPU instructions available to users by this method results in the scrapping of existing systems, resulting in a considerable burden on users.

As is evident from the foregoing, in the model expression of X2 = M - m - N*T - n*C ... (5), the implementation of "maximization of the number of CPU instructions X2 available to users" by the simplest possible method is currently demanded by industry. For this purpose, it is necessary to minimize (N*T) and (n*C).

SUMMARY OF THE INVENTION The main object of the present invention is to provide improved processing efficiency and effective use of CPU resources when multiple communication lines are connected to a computer such as personal computer or workstation.

In order to achieve the above object, the multiplex communication controller of the present invention is connected between a computer such as personal computer or workstation and multiple communication lines, said computer processes data records transmitted and received through said respective communication lines in a predetermined common record format, said multiplex communication controller converts data records in the common record format transferred from said computer to the record formats corresponding to said respective communication lines and transmits them to corresponding communication lines and also converts data records received from said respective communication lines to said common record format and transfers them to said computer.

With this arrangement, even when the computer communicates with multiple communication lines, it needs to maintain a communication line to said multiplex communication controller only.

In addition, since data transmitted and received through said multiple communication lines may be processed in the common record format, format conversion processing for different record formats for respective communication lines may be reduced, thereby reducing load on the CPU and the OS in said computer and loss time associated with data transmissionireception between said computer and the multiplex communication controller, and improving the instruction processing efficiency of the computer system.

The present invention further seeks to reduce the loss time associated with communication processing in said computer when a multiplex communication controller is connected between a computer such as personal computer or workstation and multiple communication lines. Towards achieving this objective, said multiplex communication controller collects data records received from the communication lines, then converts them to said common record format for transfer to said computer.

With this arrangement, after data records received from the same communication line or different multiple communication lines intermittently are collected into a single data record, the data record is converted to said common record format and transferred to said computer, thereby further reducing the loss time of the CPU and the OS associated with communication processing in said computer.

A theoretical outline of the present invention is given below.

By connecting a "multiplex communication controller" for controlling multiple communication lines to PC (WS) 1, N is set to 1 in model X2 in above expression (5).

In addition, n is minimized by converting data transmitted and received between individual communication lines TL1 to TL3 and PC (WS) 1 to a common record format, collecting small but repeated data transmitted and received, and performing file transfer.

If n approaches 1 limitlessly with this method, the model X2 in the above expression (5) becomes X2 = M - m - T - C ... (6) It can be seen from the above that the "multiplex communication controller having the functions of converting communication data to a common record format and collecting transmitted and received data" easily realizes "minimization" of N and n in PC (WS) 1, etc., thereby contributing to an increase in the "number of CPU instructions X2 available to users" of PC (WS) 1.

The "multiplex communication controller" of the present invention includes the following basic functions.

(a) Maintaining communication sessions with multiple opposite communication parties (one-to-N).

(b) Maintaining a communication session with PC (WS) 1 (one-to-one).

(c) Receiving data records from multiple opposite communication parties and collecting data and also converting them to a common record format (hereinafter referred to as "protocol conversion") and transferring them to PC (WS) 1.

(d) Relaying data records in a common record format transmitted from PC (WS) 1, converting them to the data record format of the opposite communication party (hereinafter referred to as "protocol reconversion"), and transmitting them to the opposite communication party.

As a result, even when PC (WS) 1 is communicating with multiple opposite communication parties, the number of communication sessions to be maintained constantly is 1 (N = 1), thereby considerably reducing load on the CPU and on the OS for the maintenance of communication sessions.

In addition, by using a common record format, the number of data transmissions to multiple opposite communication parties may be reduced (minimization of n), thus reducing more load on the CPU and the OS than conventional systems do.

Consequently, even when PC (WS) 1 communicates with multiple communication lines, it needs to maintain a communication line to said multiplex communication controller only. In addition, since format conversion processing for different record formats for respective communication lines is reduced, thereby reducing load on the CPU and the OS in PC (WS) 1 and loss time associated with communication control instructions and stand-by time occurring when multiple communication sessions are simultaneously maintained by a single PC (WS) 1, thereby improving the instruction processing efficiency of a system such as the PC (WS) 1.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 consists of equipment block diagrams showing the first embodiment of the present invention.

Fig. 2 is an equipment block diagram showing a conventional example.

Fig. 3 is a software block diagram showing a conventional example.

Fig. 4 is a software block diagram showing the first embodiment of the present invention.

Fig. 5 is a diagram showing the common record format of the first embodiment of the present invention.

Fig. 6 is a block diagram showing the second embodiment of the present invention.

Fig. 7 is a block diagram showing the third embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS The preferred embodiments of the present invention are described below with reference to the drawings.

Figs. 1 and 4 are block diagrams showing the first embodi -ment of the present invention, in which the components identical to those of the conventional example described earlier are denoted by the same symbols, thereby omitting the need for description.

Fig. 1 consists of equipment block diagrams. Fig 1. (a) shows the configuration when emulator hardware sections 2a to 2c are used. A difference from the conventional example is that there is a multiplex communication controller 6 of the present invention between emulator hardware sections 2a to 2c and PC (WS) 1. With this configuration, PC (WS) 1 is connected only to multiplex communication controller 6 via single interface board 4d mounted in a rear slot. Fig 1 (b) shows an equipment configuration when modems 3a to 3c and multiplex communication controller 6 are directly connected together by providing the multiplex communication controller 6 between modems 3a to 3c and PC (WS) 1, instead of using the emulator hardware sections 2a to 2c. In this case also, PC (WS) 1 is connected only to multiplex communication controller 6 via single interface board 4d mounted in a rear slot. Either of these configurations may be used.

Multiplex communication controller 6 comprises main control section 6a consisting of a CPU and memory, interface section 6b for PC (WS) 1 for connection to main control section 6a, and interface sections 6c to 6e for emulator hardware sections 2a to 2c or for modems 3a to 3c, 2a to 2c and 3a to 3c corresponding to respective communication lines TL1 to TL3.

Fig. 4 is a diagram showing the software configuration when emulator hardware sections 2a to 2c are not used. In this fig ure, memory space la of PC (WS) 1 includes emulator software sections lla to llc corresponding to respective communication lines TL1 to TL3, any application software 12, data distributor 13, protocol reconverter 14, and data buffer 15, in addition to the OS. Multiplex communication controller 6 includes protocol converter 16.

The operation of the first embodiment having the abovementioned configuration is described below.

When data are sent from opposite communication parties Al to A3 via communication lines TL1 to TL3, respective data items are sent to multiplex communication controller 6 via modems 3a to 3c dedicated to the respective communication lines. These data items are collected by the protocol converter 16 in the multiplex communication controller 6, then converted to a common record format and transferred to the PC (WS) 1.

The above-mentioned common record format may vary slightly depending on the application of the present invention. The format shown in Fig. 5 (a) is used as an example with the hardware and software configurations of this embodiment. Common record format 20 consists of control region 21 and user data region 22. Control region 21 includes OS control area 21A, data distribution control#area 21B, protocol reconversion control area 21C, and data buffer control area 21D. User data region 22 includes record length control area 22A and data area 22B.

OS control area 21A holds data necessary for the OS installed in PC (WS) 1 to control addresses to emulator software sections lia to lic, etc., and to distribute. Data distribution control area 21B holds complementary address data for emulator software sections lla to lic installed in PC (WS) 1, cipher data for emulator software sections lla to llc, and identification codes corresponding to the communication lines.

Protocol reconversion control area 21C holds data and flags necessary for protocol reconversion. Data buffer control area 21D holds data such as how records are stored in data buffer 15 in PC (WS) 1, addresses, and logging numbers.

Record length control area 22A holds user data properties, i.e., data indicating fixed or undefined length, etc. Data area 22B holds user data or data for emulator software in digital or analog form.

Data transferred from multiplex communication controller 6 to PC (WS) 1 in the common record format described above are accumulated in data buffer 15.

In this embodiment, a set of data in above-mentioned common record format 20 is assumed to be a single unit record data item.

Multiple unit record data items are collected to form a block record to be transferred, which is transferred from multiplex communication controller 6 to PC (WS) 1. More specifically, as Fig. 5 (b) shows, block record 30 is composed of multiple unit record data items 31 (each corresponding to common record format 20) which are connected serially, preceded by the first communication control region 32 and followed by the second communication control region 33 region. The first communication control region 32 holds information necessary for communication control such as the number of records of unit record data items 31 collected into block record 30. The second communication control region 33 hold information necessary for communication control such as end-of block of a unit record data item.

Data accumulated in data buffer 15 are reconverted to record formats dedicated to emulator software sections lla to llc by protocol reconverter 14, as required, in accordance with the instructions of the reconversion signs held in protocol reconversion control area 21C in common record format 20, and are distributed to emulator software sections lla to llc by data distributor 13 on the basis of the identification codes held in data distribution control area 21B.

It should be noted that data in common record format 20 in data buffer 15 is reusable by other user application software.

The PC user can input data to user application software 12 via protocol reconverter 14 and data distributor 13 through the necessary operation.

Data created by emulator software sections lla to llc or application software 12 are transferred to modems 3a to 3c by following the above procedure in reverse order.

More specifically, data created by emulator software sections lla to llc or application software 12 are transferred to protocol reconverter 14 via data distributor 13, where they are converted to data in common record format 20. After data are set in each control area in control region 21, the converted data are transferred to multiplex communication controller 6 via data buffer 15.

The data are converted by protocol converter 16 of multiplex communication controller 6 to the record format corresponding to communication lines TL1 to TL3 through which the data are to be transmitted, on the basis of the identification code held in data distribution control area 21B and then transmitted to an opposite communication party Al to A3 via modems 3a to 3c and communication lines TL1 to TL3.

Control instructions and synchronous stand-by time for communication session maintenance in the OS in PC (WS) 1 are only for the line between PC (WS) 1 and multiplex communication controller 6. Although instruction load occurring at this time in data buffer 15, protocol reconverter 14, and data distributor 13 is not negligible, it is more effective than OS idle time such as synchronous line stand-by time.

Consequently, this embodiment can reduce load on the CPU and OS and loss time due to communication control instructions and stand-by time occurring when multiple communication sessions are maintained simultaneously by a single PC (WS) 1, thereby improving the instruction processing efficiency of the PC (WS) 1 system.

The second embodiment of the present invention using multiple host workstations to which the above-mentioned first embodiment is applied is described with reference to Fig. 6.

The multiple host workstations in Fig. 6 may be implemented if connection between PC (WS) 1 and business-specific host computers HC1 to HC4 in a local area or a company is made via communication lines TL11 to TL14 and multiplex communication controller 6.

With this multiple host workstation system, a single PC (WS) 1 can maintain on-line terminal relations with multiple businessspecific host computers HC1 and HC4 simultaneously, resulting in improved availability such as the following.

First, availability in the use of data across businessspecific host computers HC1 to HC4 is improved dramatically.

More specifically, in the prior art, when data are to be used across business-specific host computers HC1 to HC4, the following restrictions exist for data exchange processing in host computers HC1 to HC4.

(a) It is necessary to develop dedicated software for format conversion, data integration processing, etc., requiring development time and cost for the software development. Since meticulous care and safety precautions are necessary in developing software for computers for the control of on-line software, development time and labor can be quite substantial.

(b) Due to file and database management requirements, data exchange processing on the host computer side is often difficult during on-line maintenance. For this reason, data exchange processing is generally performed by batch processing on completion of on-line maintenance. In this case, data exchange processing is not possible immediately on demand.

(c) To allow integrated data to be used on-line on completion of the exchange processing of the entire data file by batch processing, enlarging the host computer and extending the recording device are essential.

In contrast, with the multiple host workstation system of the second embodiment of the present invention, a single PC (WS) 1 can retrieve data from multiple business-specific host computers HC1 to HC4 simultaneously.

In addition, because data are converted to a common record format when retrieved from host computers HC1 to HC4, data format integration can be easily performed among host computers HC1 to HC4.

Because only data integration processing is performed using data retrieved from host computers HC1 to HC4, this may be done with software on PC (WS) 1. Furthermore, this data exchange processing is performed during the on-line processing of host computers HC1 to HC4 and therefore may be performed immediately as required. Also, since batch processing is not necessary, enlarging the host computer and expanding the recording device are not required.

Secondly, any number of user PCs (WSs) 1 may be provided depending on the needs of the business, without being restricted by the number of business-specific host computers and the number of on-line lines. More specifically, in the prior art, if online business-specific host computers each require dedicated terminals, the number of terminals necessary is equal to the number of on-line lines in each company branch office. With the multiple host workstation system of the embodiment of the present invention, a single PC (WS) 1 may be an on-line terminal for multiple business-specific host computers HC1 to HC4.

The third embodiment of the present invention using multiple input workstations to which the above-mentioned first and the second embodiments are applied is described below referring to Fig. 7.

With the multiple host workstation system of the abovementioned second embodiment, single PC (WS) 1 is connected to multiple business-specific host computers HC1 to HC4 via multiplex communication controller 6 and functions as an on-line terminal. The multiple input workstation system is the system in which the software to be described later is installed in PC (WS) 1 as shown in Fig. 7 to improve user availability.

The software installed in PC (WS) 1 includes, in addition to the OS, data distributor 13, protocol reconverter 14, data buffer 15, emulation software sections 17a to 17d, and front-end user interface software 18.

The functions and availability of this system are as follows.

(a) Shadow emulation Shadow emulation means that the user need not directly handle emulation software sections 17a to 17d. More specifically, on-line emulation software sections 17a to 17d for businessspecific host computers HC1 to HC4 are packaged and placed under the control of front-end user interface 18. This allows the user to access data in host computers HC1 to HC4 without needing to handle emulation software sections 17a to 17d.

This allows automatic data entry and automatic data reference, permitting automatic execution of data exchange processing among host computers HC1 to HC4 without operator intervention.

(b) Front-end user interface The user can operate the emulation software sections 17a to 17d which are under the control of front-end user interface software 18, merely by running a simple program for PC (WS) 1 on the front-end user interface software 18.

Consequently, the user can access data in host computers HC1 to HC4 to issue instructions for executing data exchange process ing among host computers HC1 to HC4 and also refer to data in host computers HC1 to HC4 to retrieve them into a user program on PC (WS) 1, without handling emulation software sections 17a to 17d.

(c) Data buffer By adding the virtual logging function of a magnetic hard disk device to data buffer 15, data integrity and safety may be improved in the automatic entry function in shadow emulation in (a) above and in data exchange processing among host computers HC1 to HC4.

By accumulating data of host computers HC1 to HC4 to be referenced regularly and constantly, the number of times each terminal accesses host computers HC1 to HC4 may be reduced.

It should be noted that the above-mentioned first to third embodiments are simply typical embodiments of the present invention and that the equipment configuration, the type of software installed in PC (WS) 1, the common record format, etc., are not limited to those described thus far.

Claims (7)

Claims

1. A method of multiplex communication control for computers wherein a multiplex communication controller is connected between a computer such as personal computer or workstation and multiple communication lines, said computer processes data records transmitted and received through said respective communication lines in a predetermined common record format, said multiplex communication controller converts data records in the common record format transferred from said computer to the record formats corresponding to said respective communication lines and transmits them to corresponding communication lines and also converts data records received from said respective communication lines to said common record format and transfers them to said computer.

2. The method of multiplex communication control for computers of claim 1 wherein said multiplex communication controller collects data records received from communication lines, converts them to said common record format, and transfers them to said computer.

3. A multiplex communication controller connected between a high order device such as computer and multiple communication lines comprising a data input/output means for outputting and inputting, to and from said high order device, data records in a predetermined common record format including identification codes representing the types of said communication lines a data transmitting means for converting data records in said common record format input from said high order device via said data input/output means to the record formats for the corresponding communication lines on the basis of said identification codes and transmitting them to the communication lines, a data receiving means for converting data records received from said respective communication lines to data records in said common record format, adding to them identification codes corresponding to the communication lines from which they are received, and outputting them to said high order device via said data input/output means.

4. The multiplex communication controller of claim 3 wherein said data receiving means collects data records received from communication lines, converts them to said common record format, and transfers them to said computer.

5. A method of multiplex communication control substantially as herein described with reference to the accompanying Fig. 1 and Figs. 4 to 7.

6. A multiplex communication controller substantially as herein described with reference to the accompanying Fig. 1 and Figs. 4 to

7.