JPH0372729A - Data carrier - Google Patents

Abstract

PURPOSE:To discriminate the error of a data carrier to facilitate its maintenance by providing a memory with an error log area where error contents are held. CONSTITUTION:Data is transmitted between a data carrier 4 holding data attached to an article or the like and a write/read control unit, and the data carrier 4 discriminates error of data communication by an error discriminating means 5 at each time of data transmission. If error is discriminated, its contents are stored in the error log area of a memory 1. Thus, the error log area of the data carrier is only checked to easily detect the abnormal state, and the data carrier where the frequency of error is high is specified, and its maintenance is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data carrier for holding data, which is used in the management of machine tools, parts in factories, product management, logistics systems, etc.

[Conventional technology]

In order to mechanize the tool management of conventional machine tools and the identification of parts and products on assembly lines in factories, tools 1
A system is needed to identify and manage various items such as parts and products. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 63-221950, a data carrier having a memory is provided in the object to be identified, and the necessary information is written in such memory by external data transmission, and the information is read as necessary. An article identification system has been proposed in which the article is displayed on the screen.

[Problem to be solved by the invention]

However, according to such conventional identification systems,
Noise may be added to a data carrier that holds data, or noise may be superimposed during data transmission, resulting in communication errors. Such errors include those caused by the ID controller and those caused by the data carrier. However, since data carriers are attached to, for example, balents and transported on the article transport line, it is difficult to determine which data carrier caused the error even if the ID controller retains an error during data transmission. The drawback was that it couldn't be done.

The present invention has been made in view of the problems of error detection in conventional article identification systems, and its technical problem is to identify errors in data carriers and facilitate maintenance thereof. .

[Means to solve the problem]

As shown in FIG. 1, the present invention comprises a memory 1 that holds data, a memory control means 2 that controls writing and reading of data to the memory, and a memory control means that demodulates commands and data given from the outside. The data carrier 4 has a data transmission means 3 for transmitting data read out from the data carrier, and is attached to an article to be identified, the data carrier having an error determination system for determining a transmission error each time data is transmitted by the data transmission means. The present invention is characterized in that the memory has an error log area for holding the contents of an error every time an error is determined by the error determining means.

[Effect]

According to the present invention having such characteristics, data transmission is performed between a data carrier holding data attached to an article, etc., and a write/read control unit consisting of a read/write head and an ID controller, The data carrier uses an error determining means to determine a data communication error for each data transmission. If an error is determined, it is stored in an error log area in the memory of the data carrier.

〔Example〕

FIG. 2 is a block diagram showing the structure of an article identification system according to an embodiment of the present invention. In this figure, the article identification system uses a pallet 11 on which parts to be identified are transported.
A data carrier 12 that is directly attached to the data carrier 12, a read/write head (hereinafter referred to as RW head) 13 that writes and reads data to and from the data carrier 12, and an RW head 1.
ID controller 1 connected to 3 to control its operation.
4 is provided. The RW head 13 and the ID controller 14 form a write/read control unit. Also ID
The controller 14 is connected to a host computer 15.

Now, the bottom of the data carrier 12 will be explained with reference to FIG. In FIG. 3, a transmitting/receiving section 21 receives and transmits a frequency signal emitted from the RW head 13, and its reception output is given to a demodulation circuit 22. The demodulation circuit 22 demodulates this signal and provides its output to the decoding circuit 23. The decoding circuit 23 decodes the encoded data into an original signal and provides it to the CPU 24. C.P.
A memory 25, for example, a static RAM bank-amplified by a buffer 26 or an E2FROM, is connected to the U24 via a bus. The CPU 24 is distantly related to the function of the memory control means 2 that controls writing or reading of data according to commands and data given from the ID controller 14, and the read data is converted into a serial signal and sent to the encoding circuit. Given to 27. The encoding circuit 27 encodes the applied signal, and its output is applied to the transmitting/receiving section 21 via the modulating circuit 28. The transmitting/receiving section 21 provides a signal to the RW head 13 by changing the resonance frequency of a resonant circuit, for example, as in the conventional example.

FIG. 4 shows a memory map of the data carrier 12. As shown in this figure, the memory 25 of the data carrier 12 has, in addition to a data area 25a, an error log area 25b in which, for example, 30 error codes are written.

Next, the operation of this embodiment will be explained. FIG. 5 is a flowchart showing the operation of the data carrier. In this figure, when the data carrier 12 receives a command from the ID controller 14 via the read/write head 13,
First, the process proceeds to step 41 to check for CRC errors. Here, the read/write head 13 sends the data carrier 12 a read command with CRC data added in addition to the address and number of read bytes to be read from the data carrier, as shown in FIG.

Therefore, in step 41, the CP of the data carrier 12
U24 performs a CRC check, and if there is no CRC error, the process advances to step 42 and checks for command errors. If there is no command error, the process further advances to step 43 to check for address errors. This is done depending on whether an address other than the address of the memory 25 held in the data carrier 12 is specified. If there is no error as a result of such an error check, read or write processing is performed based on the given command (routine 44). On the other hand, if there is an error in the steps 41 to 43, the process proceeds to step 45, and an error code indicating the content of the error is registered in the error log area 25b. After any of the processes, the process proceeds to step 46, where the data carrier 12 sends a response to the read/write head 13 side indicating that the result of the read/write process or the error code has been registered, and the process ends. Here, the CPU 24 achieves the function of the error determining means 5 which determines a transmission error every time data is transmitted in steps 41 to 43. In this way, the data carrier 12 determines the presence or absence of an error every time data is transmitted, and if an error occurs, it sequentially records an error code in the error log area. Once error codes have been written to all areas of the error log area, the oldest error code is then deleted and a new error code is written to ensure that the latest error code is always maintained in the error log area. . If there is a continuation command for the error log area from the higher-level ID controller, the error code can be recognized on the ID controller side by reading the error code from this area. Therefore, if there are many errors specific to the data carrier, the condition can be easily recognized, and the data carrier can be easily replaced.

〔Effect of the invention〕

Therefore, according to the present invention, by simply checking the error log area of the data carrier, it is possible to check whether normal transmission is being performed or whether the data carrier has detected an abnormality caused by the data carrier such as battery consumption or an abnormality caused by the ID controller. Can be easily detected. Therefore, data carriers with many errors can be identified, and the entire article identification system can be easily maintained.

[Brief explanation of drawings]

Figure 1 is a functional block diagram showing the overall configuration of the present invention, Figure 2 is a functional block diagram showing the overall configuration of the present invention.
3 is a block diagram showing the structure of the data carrier, FIG. 4 is a memory map of the data carrier, FIG. 5 is a flowchart showing the operation of the data carrier, and FIG. 6 is a perspective view showing the overall configuration of the article identification system. FIG. 2 is a diagram showing an example of a command sent from an ID controller to a data carrier. Fig. 1 1--Memory 2--Memory control means 3--Data transmission means 4. 12------
Data carrier 5.--Error determination means 13
-----Read/write navel l' 14--1 ID
Controller 15-----First-level computer
24-------CP U25----Memory 4-------- ゛′′-g failure

Claims (1)

[Claims] (1) A memory that holds data, a memory control means that controls writing and reading of data to the memory, demodulating commands and data given from the outside, and transmitting the read data to the memory control means. a data carrier attached to an article to be identified, the data carrier having an error determining means for determining a transmission error each time data is transmitted by the data transmitting means; A data carrier characterized in that it has an error log area that retains the contents of an error every time an error is determined by an error determining means.