JPS6198480A - Data transmitting system - Google Patents

Abstract

PURPOSE:To improve the efficiency of data retransmission by storing up to where the date are transmitted, when transmitting data are blocked and successively transmitted and sending from the non-transmitted data block at the time of retransmission due to a circuit trouble, etc. CONSTITUTION:A terminal composed of slave POS terminals S1-Sn and a master machine M receives a transmitting command which designates a transmitting data quantity for one time from a processor 1 through a line 3. Control parts 6 and 9 of the master machine M and the slave machines S1-S2, while they refers to address information of an (a) column and data quantity information of a (b) column, transmit data D1-d1 of the files 7 and 11 through a line 3 to a processor 1 successively, and then, since address information of transmitting data is stored in memories 8 and 10, when the data is retransmitted due to a line trouble, the data transmitting is restarted from the next of the address stored at the memories 8 and 10, and therefore, the efficiency of retransmitting is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to improvement of a data transmission method for transmitting data from a PO8 terminal to a processing device in a center.O When a failure such as line disconnection occurs during data transmission. In this case, retransmission of data results in K, but there is a need to improve the transmission efficiency during this retransmission.

[Conventional technology]

A conventional example will be explained with reference to the drawings. Figure 2 shows the conventional PO
This is a block diagram showing the configuration of the S (point of sale) system for an 0PO8 terminal.

There are two types of slave machines, S and -Sn, which are connected subordinately to the master machine N, and data transmission and reception to and from the center processor IK is performed through the transmission/reception control unit 2 of the mask machine M.

Mask machine M and slaves MS+ to Sn are directly behind N.

Upon receiving the command R from the processor 1, transmission of settled transaction data is started. Transaction data D is transmitted in predetermined units (for example, 2 blocks), but during transmission, 7 times
If a disturbance occurs in 1s3 due to external noise N&ζ, a data error will occur on the receiving side (center). At times like this,
Each PO8 terminal will retransmit data, including data that has already been transmitted.

[Problem that the invention seeks to solve]

When retransmitting the transaction data as described above, there is a problem that it takes time to retransmit data when a large amount of transaction data is involved, which increases the cost of using the line and puts a burden on the processor that processes the data.

[Failure to solve the problem]

The problem mentioned above is that the terminal and the processing section are connected by a line,
In the 7th stem in which the terminal transmits data after receiving a transmission command from the processing section, a storage section that stores the data to be sent, a means for reading out and sending out the data in the storage section in units of a predetermined amount; The terminal device is provided with an address storage section for storing address information of the read data and a means for updating the address information in the address storage section, and the terminal device that receives the transmission command updates the data in the storage section. The terminal updates the address information in the address storage section every time a message is sent, and when the transmission command is received again when the transmission is incomplete, the terminal updates the address information in the address storage section based on the address information in the address storage section. This problem is solved by the data transmission method of the present invention, which transmits only the data to be transmitted to the processing device.

[Effect]

As described above, when the terminal device according to the present invention reads and transmits data in the storage section, there is a means for storing address information related to the read data, and in the case of A, only unsent data can be transmitted. Increased efficiency.

〔Example〕

Hereinafter, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram illustrating one embodiment of the present invention.

A command R is issued from the center processor 1 to the PO8 terminal to instruct data transmission. This command R is received by the transmission/reception control section 2 of the mask machine M via the communication control device 4, line 3, and communication control device 5! After being received, the slave devices 81 to Sn are also notified. Note that this command R includes information specifying the amount of data to be transmitted (for example, U
P=2> is included.

In the mask machine M, after writing the data amount information (UP=2) in column b of file 7 in control unit 6, take out the address information (starting address of file 7) A+ in column a and write it down. 1.13 K is set to 0. Then, the control unit 6 sets the data in the file 7 in units of 2 blocks (location specified by UP=2: D+ + Dt
) and sends it to the transmission/reception control unit 2, and adds fi(2) to the address information A1 in the memory 8, updating the value to (A++2).

In this way, the data is transmitted in units of two blocks, and the address information of the data extracted from the file 7 is updated (A+2n) in the memory 8.

Other PO8 terminals, such as slave machine sl or 5nVC
The same is true for MN, K for output and transmission, and control unit 9.
The address information in the memory 1o is updated and recorded.

If a line failure occurs due to external noise N during the above data transmission, a data error will occur on the receiving (center) side, so the processor 1 issues a command R requesting data transmission again.

When the mask machine M and the slave machines S, ~Sn re-receive this command R, for example, in the mask machine M example, the control unit 6
checks the address information of memory 8 and if the value is (for example, A, + 6), reads data from the address next to the address (A, + 6) and starts data transmission. . Similar data read control is performed in the other slave machines 81 to Sn.

〔Effect of the invention〕

This has the effect of improving transmission efficiency.

[Brief explanation of drawings]

Figure 8g1 is a block diagram explaining an embodiment of the present invention, Figure 2 is a block diagram explaining a conventional example. , 4.5 is the communication control device i, 6.9 is the control unit, 7,1
1 is a file, 8 and 10 memories, M is a PO8 terminal (
mask machine), "H+ Snakepos terminal machine (slave machine).

Claims (1)

[Claims] In a system in which a terminal device and a processing section are connected by a line, and the terminal device receives a transmission command from the processing section and sends out data, there is a storage section that stores the data to be sent, and a storage section that stores the data in the storage section. The terminal device is provided with means for reading and transmitting the data in units of a predetermined amount, an address storage section for storing address information of the read data, and means for updating the address information in the address storage section, The receiving terminal updates the address information in the address storage section each time the data in the storage section is sent, and when the terminal receives the transmission command again at the time when the transmission is not completed, the terminal updates the address information in the address storage section. A data transmission method characterized in that only untransmitted data in the storage unit is transmitted to the processing device based on address information of the processing device.