GB2273590A - Batch processes for data transmissions. - Google Patents

Abstract

A process for transmission of data from a plurality of remote systems (2) to a host system (1). At each remote system, a counter is incremented each time data is written to a new file and a counter value is incorporated in the file name. At a host computer, as data is successfully received, the counter value is detected and is processed automatically to determine a logical value which should correspond to a stored value. At each remote system, the counter is re-set if data transmission is successful. If data transmission is not successful, the counter value at the subsequent transmission bears an offset which indicates the failed transmission, and can be subtracted to provide the correct counter values for the filenames. <IMAGE>

Description

"Automatic Data Transmission" The invention relates to automatic data transmission where there is at least one data processing system communicating with another remote system. In this specification the phrase "automatic data transmission' means the initiation and carrying our of a data transmission session without the need for user instractions. In particular, the invention relates to such transmission in batch processes such as overnight where data which has been generated and logged during the day is to be transmitted.

PCT Patent Specification No. WO 87/05135 describes a method for data -exchange between a first and a second processor. The processor ready to receive responds to the announcement of the processor ready to transmit, which in turn acknowledges the response of the processor ready to receive. In total, there are two interrogations, whereby both processors would want to transmit at the same time.

This Specification does not disclose a method for automatic data transmission as part of a batch process, in which recognition of data files and routing of the files to the relevant storage device locations is important.

Statements of Invention According to the invention there is provided an automatic data transmission method carried out between a host computer system and a plurality of remote systems, the process comprising the steps of: the host computer system generating a data structure whereby there is a data file for each of the remote systems; a processor in each remote system writing data immediately it is received to one of a plurality of files, the file being selected according to the nature of the data which is received; the processor of a remote system incrementing a counter each time data is written to a new file in a pre-set time period, and setting the file name according to the value of the counter;; the host computer by reference to an on-board real-time clock automatically generating poll signals at the end of the time period and transmitting the poll signals simultaneously to each of the remote systems; on receipt of a poll signal, a remote system transmitting communicating signals to the host computer and establishing a communications session and subseauently transmitting the data files; if the communications session is successful the remote system deleting the data in the files of the storage device and resetting the counter; and the host processor determining the counter value within the name of each file which is received and processing the counter value to determine a logical counter value which should correspond to one of a set of pre-stored values to ensure that if the file contains data for two time periods where the counter has been incremented twice, the logical value corresponds to the pre-stored value.

In one embodiment, the step of re-setting a file name according to the counter value is carried out after data transmission even if new data has not been written to the file during the time period.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, given by way of example only with reference to the accompanying drawings in which; Fig. 1 is a diagrammatic view showing a host computer system communicating with a number of remote systems; and Fig. 2 is a flow chart illustrating batch processed data transmission between the systems.

Referring to the drawings, and initially to Fig. 1 there is shown a host computer system 1 which is constructed for communication with remote systems 2. Communication is via a modem and leased lines operating at 4800 baud. Each remote system 2 comprises a microcomputer 3 connected to a registere controller which controls a bank of cash registers in a retail store. The microcomputer 3 is also connected to a fixed disk drive 5 for storage of data.

In operation, data is received at the register controllers 4 of each of the remote systems 2. This is automatically transmitted to the microcomputers 3, which in turn write the data to databases stored on the fixed disk drives 5.

This data reception for processing continues on an ongoing basis during the working day. Much of the data will relate to sales volumes for products in the retail store.

Referring to Fig. 2 operation of an automatic data transmission method of the invention is indicated by the numeral 10.

The host computer 3 generates a data structure in a storage device to which it is connected by which there is a separate file for each of the remote systems 2. This is indicated by the step 11 in Fig. 2. In step 12, each microcomputer 3 writes received data to a particular file in the fixed disk drive 5 to which it is connected. For example, one file may relate to sales levels, whereas another would relate to stock. levels. As data is written to each file in turn, a counter is- incremented and the value of the counter is written into the file header as the name of the file.For example, the first file which is written to may be called RETAIL.000. When the microcomputer 3writes to the next file with a different type of data the counter is incremented to 1 and the name of the second file becomes RETAIL.001. In this embodiment, six files are generated by each remote system 2 during processing. Each remote system has a different first portion for its file name. The step of incrementing the counter is indicated by the numeral 14 for each file to which data is written. Steps 12, 13 and 14 are repeated during the working day as data is received at the microcomputer 3 in each remote system 2.

When all of the six files in each system 2 have been written to there exists six files. In one system 2, these are named RETAIL.000, RETAIL.001, RETAIL.002, RETAIL.003, RETAIL.004 and RETAIL.005. At a particular time in each twenty-four hour period, the host computer automatically generates a polling signal with reference to a real-time clock in step 15. This is simultaneously transmitted to each of the remote systems 2 via the leased lines. Upon receipt of a polling signal, the microcomputer 3 of each remote system 2 attempts to establish a communications session with the host computer 3 and to transmit the data files. If any file has not been written to during the day, its name extension is assigned the next counter value, for example 001 or 002.If the communications session is successful and all data has been safely received, as indicated by the decision step 17, in step 20 the microcomputer automatically resets the counter to 0 and resets the file name extensions to .000 for each of the files. However, if the communications session has not been successful, in step 18 the microcomputer 3 monitors the counter value and writes any fresh data to a different par= of the same file. This is indicated by the step 18 and the subsequent step 12. However, this time as the counter is incremented the file numbers become RETAIL.006 to RETAIL.012. Because the host computer is automatically constructed to recognise certain file names this would pose a problem.This is overcome by the technical step of the host computer processing the file name according to an algorithm to determine a logical name which should correspond to that which is expected. In this embodiment the processing is carried out as follows: Divide the counter value by 6 e.g. 13 / 6 = 002 Multiply answer by 6 002 * 6 = 012 Subtract from original counter 013 - 012 = 001 Therefore the logical file name is RETAIL.001.

In this way, the host computer 1 will recognise the file and be in a position to automatically transmit it to the correct storage device, the files being stored separately according to their associated remote system 2. At the end of the session, the host computer automatically writes the data to relevant information processing files for generation of management reports or other processing.

In the invention, an automatic batch process of transmitting data at regular time periods from remote systems to the host system is carried out efficiently and in a manner which ensures that if a communications session fails all of the data is transmitted in a simple manner at the following time period and may be logged accordingly at the host compu#ter. Thus, all data logged at a remote system 2 is automatically transmitted to the host computer 1. This is very important for such host computer -operations as management information reporting because a large "pool" of data is available on a timely basis.

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

Claims (3)

1. An automatic data transmission method carried out between a host computer system and a plurality of remote systems, the process comprising the steps of: the host computer system generating a data structure whereby there is a data file for each of the remote systems; a processor in each remote system writing data immediately it is received to one of a plurality of files, the file being selected according to the nature of the data which is received; the processor of a remote system incrementing a counter each time data is written to a new file in a pre-set time period, and setting the file name according to the value of the counter; the host computer by reference to an on-board real-time clock automatically generating poll signals at the end of the time period and transmitting the poll signals simultaneously to each of the remote systems;; on receipt of a poll signal, a remote system transmitting communicating signals to the host computer and establishing a communications session and subsequently transmitting the data files; if the communications session is successful the remote system deleting the data in the files of the storage device and resetting the counter; and the host processor determining the counter value within the name of each file which is received and processing the counter value to determine a logical counter value which should correspond to one of a set of pre-stored values to ensure that if the file contains data for two time periods where the counter has been incremented twice, the logical value corresponds to the pre-stored value.

2. An automatic data transmission method as claimed in claim 1, wherein the step of re-setting a file name according to the counter value is carried out after data transmission even if new data has not been written to the file during the time period.

3. An automatic data transmission substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.