JPS63225842A - Data write system for id system - Google Patents

Abstract

PURPOSE:To improve the reliability of data write by comparing data before write with read data after write and restoring and transmitting write data corresponding to a write unit (one page) preliminarily stored at the time of preceding read processing in case of disaccord between them. CONSTITUTION:Read data after write which is added to the read response and is sent is compared with data before write, which is preliminarily stored in a buffer memory, in the side of an ID controller 10, and a normal write response is sent to a higher computer as OK if they coincide with each other. If they do not coincide with each other, one-page components of data stored in the buffer memory are added to the write response and are sent back from a higher transmission part 15 to the higher computer. When receiving this write response with data, the higher computer judges that current write is not normally performed, and a proper processing such as write to another address or the like is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial field of application This invention is applicable to the control of a host computer, such as ID
from a first device, such as a controller, via a transmission medium.
The present invention relates to a data writing method for an ID (identification) system that transmits data to a second device, which is a data carrier including a memory such as an E-FROM, or reads data from a memory.

(B) Conventional technology In recent years, for example, ID systems for identifying the type of articles, tools, etc. transferred on a conveyor have been used to identify the type of articles, tools, etc.
A device in which a device called a data carrier including a memory is attached, and a controller writes specific data into the memory of the data carrier, or conversely reads the data, is being considered. An EE-PROM is used as a memory for this data carrier.

In this ID system, when writing data from the ID controller to the EE-FROM, which is the memory of the data carrier, the EE-FROM usually has a configuration in which 8 bytes constitute one page, and when writing data, the data is written in page units. I can only write in it. In other words, in the conventional ID system, the data carrier has 8 bytes (one page) of RA, M? A separate iI area is provided, and when writing data, the contents of the page to be written in EE-FROM are stored in RAM.
Part of the data must be moved to the eJf area and the data must be rewritten (
Example: After rewriting only 1 byte of data in the RAM area, the contents of the RAM wi area are written all at once to the EE-PROM.
It's getting old.

(c) Problems to be Solved by the Invention However, in general, there is a limit to the number of times that EE-FROM can be written to.For example, if it exceeds 10,000 times, the reliability of the written data will drop significantly, and in the unlikely event that a writing error occurs. When this occurs, there is a problem in that not only does the reliability of the data on that page become low, but also that the destroyed original written data cannot be reproduced.

Additionally, if the data in the address area of the EE-FROM that has been written 10,000 times is destroyed and becomes unusable, the entire EE-FROM becomes unusable, and the life of the data carrier ends there. there were.

In view of the above, the present invention provides an EE/FROM of the second device.
EE-F.
The purpose of this invention is to provide a data writing method for an ID system that can effectively utilize memory such as ROM.

(d) Means and operation for solving the problem When normal reading and writing is performed, first, the previous data at a certain address is read, and then new data is written at the same address based on some result. In other words, write processing following read processing is often performed in pairs. This invention takes advantage of such a case.

The data writing method of the ID system of the present invention transmits data to be written from a first device to a second device via a transmission medium, and writes data to an electrically readable/writable memory provided in the second device. This is a data writing method in which reading data from the memory using a read command and a write command to the same address as the read command are consecutive, and the read command causes data to be written to the memory. , reads out data in an area corresponding to a rewrite unit of the memory including the same address, stores it in a temporary storage means provided in the first device, and in response to the next subsequent write command, reads the data in the area corresponding to the rewrite unit of the memory, and in response to the next subsequent write command, reads the data in the area corresponding to the rewriting unit of the memory write the written data to the same address in the memory of the second device, and then send a read command from the first device to the second device to read the data written this time from the memory and write the data before writing. The data stored in the temporary storage means is compared with the read data, and if a match is obtained, a normal write response is output, and if a failure is not obtained, a response indicating that is appended with the data stored in the temporary storage means is output. I try to do that.

In this data writing method, for example, data for one page (8 bytes) of the EE-PROM is read out and stored at the time of the previous address specification, including one page containing that address. In the current write process, new data is written, the written data is read to the first device, the data before reading and the data after writing are compared, and if the two match, the writing is started. In this case, the write response is transmitted to the upper side, and if a match is not obtained, it means that the write was not performed correctly, so in this case, it is necessary to indicate that. The response and the unwritten data stored for one page during the previous read are determined to be correct and transmitted to the upper side. This allows the higher-order side to specify another address and perform another write without compromising reliability, if necessary.

(e) Examples Hereinafter, the invention will be explained in more detail with reference to Examples.

FIG. 2 is a block diagram of an ID system showing an embodiment of the present invention.

This ID system uses the ID controller ID and this
It is composed of a read/write head section IDa connected to the D controller ID, and a data carrier 20 to which power is electromagnetically supplied via the read/write head section IDa, and data is also exchanged electromagnetically. .

ID The controller ID sends commands to the CPU 1, the program memory 12, the RAM 13 for temporary data storage, the timer 14 for time measurement, the upper transmission section 15 for connecting to the upper computer, the lower data carrier 20, Lower-side modulation/demodulation circuit 16 that sends and receives data, etc.
This ID controller ID receives commands from a higher-level computer, converts them into commands that can be transmitted to a data carrier 20, which is a lower-level device, and transmits data. This is a controller that performs control for converting.

FIG. 3 is a block diagram showing a specific configuration of the data carrier 20, in which the data carrier 20 decodes a transmission signal from the modulation/demodulation circuit 21 coupled to the read/write head section IDa of the ID controller ID. a decoding circuit 22 for decoding, a serial input circuit 23, a command decoder 24 for decoding input commands, a data buffer 25, an EE-PROM 26 to which data to be stored is written or read, and this EE-PR
It is comprised of a serial output circuit 27, an encoding circuit 28, etc. used when reading data from the OM 26.

Each circuit section constituting the data carrier 20 has a logic configuration using various combinations of gates. EE
- Various data are written and read from the PROM 26 on a page-by-page basis, each page having 8 bytes. The data carrier 20 does not have a built-in power supply circuit, and is configured such that power is electromagnetically and contactlessly supplied from the ID controller ID through the modulation/demodulation circuit 21.

FIG. 4 is an external view of the ID system of the embodiment, in which the read/write head section IDa and the ID controller ID are connected by a lead wire IDb, while the data carrier 20 is formed of one chip, as described above. , are attached to items, tools, etc. that are transferred on a conveyor,
In the process of transporting these items and tools, the read/write head section I is operated under the control of the ID controller ID.
It is configured such that data can be written to the data carrier 20 via the data carrier 20, or data can be successively outputted from the data carrier 20 via the read/write head section IDa to the ID controller ID and further to higher-level equipment.

Next, the data write operation in the above embodiment ID system will be explained with reference to the flowchart shown in FIG. In Figure 1, the left column shows commands from the host computer, and the middle column shows ID controller processing.
Furthermore, the right column illustrates the processing of the data carrier in relation to it.

In this embodiment ID system, it is assumed that a read command of the same address is preceded by a write command. Therefore, first, the read command is sent from the host computer to the ID controller ID (step 5Tl
). This read command consists of a command code, a start address, and the number of bytes of data to be read.

In response to a read command, the ID controller ID creates a read command for the same page (8 bytes) to which the address of the read command belongs, and sends it to the data carrier 20.
(Step 5T2).

The data carrier 20 reads one page of data including the corresponding same address (step 5T3), and returns a read response with data to the ID controller ID side (step 5T4).

In the ID controller ID, this address and 8 bytes of data are stored in the buffer memory, that is, RAM 13 (step 5T5), and a read response is sent to the host computer (step 5T6). The data to be sent is only that corresponding to the specified address.

Next, a write command is input from the host computer (step 5T7). This write command consists of a command code, a start address, and write data to be written.

Upon receiving this write command, the ID controller ID side rewrites only predetermined data from the corresponding address in the buffer memory, apart from the data at the time of reading (step 5T8), and transmits the write command with the data to the data carrier 20. (Step 5T9). In this case, the data is only the specified write data. In the data carrier 20, upon receiving this write command, the EE-PR
The data in the specified address area of M26 is rewritten with new data (step 5TIO), and the write response is returned to the ID controller ID side (step 5TII). When the ID controller IO side receives this write response, it sends a read command again (step 5T12), and the data carrier 20 side that received this read command reads the data, that is, reads only the data written this time ( Step 5T13),
The read response with the data attached is returned to the ID controller ID side (step 5T14). ■On the D controller IO side, the post-write read data sent with the read response this time is compared with the pre-write data stored in the buffer memory in ST8, and if they match, it is considered OK. A normal write response is sent to the host computer (step 5T16), but if a match is not obtained, one page of data stored in the buffer memory (ST5) is attached to the write response and returned to the host computer. do.

When the host computer receives a write response with this data, it must determine that the current write was not successful and take appropriate processing, such as writing to a different address again. Can be done.

In this embodiment ID system, there is a buffer memory for storing read data, a write data buffer memory for storing write data, and a comparison of data before writing and data after writing read from a data carrier. Since this is done on the ID controller side, the logic on the data carrier side can be made as small as possible, which can reduce power consumption on the data carrier side.
This is very effective when supplying power to the ID controller without using batteries.

(F) Effects of the Invention According to this invention, even if the write data sent from the ID controller is not written correctly, the data before writing and the read data after writing are compared, and if a match cannot be found, In this case, the write data corresponding to the rewriting unit (1 page) that is stored in advance during the read processing that is prefaced is restored and sent, so that data can be used again to write data to a different memory address that will not cause an error. Therefore, there are advantages in that data writing reliability can be improved and memory can be used effectively.

[Brief explanation of drawings]

FIG. 1 is a flow diagram for explaining the write operation of an ID controller according to an embodiment of the present invention, FIG. 2 is a block diagram of an ID system according to an embodiment of the present invention, and FIG. FIG. 4, a block diagram of a data carrier of the ID system, is a schematic external perspective view of the ID system. ID: ID controller, IDa: read/write head section, 11: CPU of ID controller. 13: RAM, 20: Data carrier, 26: EE
-PROM. Patent applicant Tateishi Electric Co., Ltd. Agent
Patent Attorney Shigeru Nakamura Nobushin 1 Figure 2

Claims (1)

[Claims] (1) A data writing method in which data to be written is transmitted from a first device to a second device via a transmission medium, and written into an electrically readable/writable memory provided in the second device. , a data writing method for an ID system in which reading of data from the memory by a read command and a write command to the same address as the read command are consecutive, wherein the read command causes the same address to be read from the memory. The data in the area corresponding to the rewriting unit of the included memory is read out and stored in a temporary storage means provided in the first device, and in response to the next subsequent write command, the data attached to the write command is read out and stored in the temporary storage means provided in the first device. Write to the same address in the memory of the second device, and then send a read command from the first device to the second device to read the data written this time from the memory and read it as the data to be written before writing. The ID system outputs a normal write response if a match is found, and a response indicating that if a match is found, with the data stored in the temporary storage means attached to the response. data writing method.