JP2993008B2 - Article identification system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for a machine tool, a component and a product in a factory, and an article identification system used for a distribution system or the like.

[Conventional technology]

2. Description of the Related Art Conventionally, a system for identifying and managing various articles such as tools, parts, products, and the like is required to mechanize the management of tools of machine tools and the identification of parts and products on an assembly and transfer line in a factory. Therefore, a memory unit having a memory for an object to be identified is provided as in JP-A-63-221950, and necessary information is written into such a memory by external data transmission, and the information is read as necessary. There has been proposed an article identification system in which a product is issued.

In such an identification system, a data carrier having data is mounted on a pallet or the like on a transport line, and a write / read control device for performing data transmission with the data carrier is fixed to a side of a transmission path. The writing / reading control device performs data transmission only when the pallet having the data carrier reaches the communication area. An auto command mode is provided in which commands are continuously transmitted at predetermined time intervals until the data carrier reaches the communication area of the write / read control unit. FIG. 6 is a diagram showing an access flow in the auto command mode. When an auto read or auto write command is sent from the host computer, the ID controller receives and decodes the command and accesses the data carrier at predetermined intervals. Send a command. The transmission of this command is continued until the data carrier approaches, the data carrier reaches the communicable area and the command is received,
When the response is transmitted, the ID controller receives the response from the data carrier, performs processing, transmits a response to the auto-read or auto-write command to the host computer, and ends the processing.

[Problems to be solved by the invention]

In such a conventional identification system, an unstable communication area A2 exists around a stable communication area A1 in the write / read control device as shown in FIG. If a command is sent when the data carrier enters the unstable area, an error is likely to occur. However, in the conventional identification system,
If an error occurs during access in the unstable area when the data carrier approaches when transmitting in the auto command mode, the auto command is stopped immediately at that point, so when the data carrier enters the stable communication area after that, However, there is a disadvantage that data communication cannot be performed.

The present invention has been made in view of such a problem of the conventional article identification system, and sends a command again even if there is a transmission error in a data carrier in an unstable area when sending a command in the auto mode, A technical task is to make it possible to execute an autocommand.

[Means for solving the problem]

According to the present invention, as shown in FIG. 1, a memory 1 for holding data, a memory control means 2 for controlling writing of data to the memory or reading of data from the memory, and demodulating a command given from the outside. A data carrier 4 attached to an article to be identified and transmitting data to the data carrier or receiving data sent from the data carrier; And a write / read control unit 6 having a data transmission means 5 for transmitting data to the data carrier via the data transmission means. When a carrier absent error occurs, a command is repeatedly sent and the data carrier is written /
An automatic command transmitting means 7 for transmitting a command until a predetermined number of access errors occur when the apparatus is located in an unstable communication area in communication with the read control unit.

[Action]

According to the present invention having such a feature, when data is transmitted by the auto command, the transmission of the command is repeated until the data carrier approaches. Even if an error occurs during data transmission even when the data carrier approaches, the command is transmitted until the access error reaches a predetermined number. If normal access is possible before this counter counts up, the auto command is executed. Command transmission has stopped.

〔The invention's effect〕

Therefore, according to the present invention, when the data carrier approaches the write / read control unit and reaches the unstable communication area, even if an access error occurs at the time of access, a command is transmitted again until a predetermined number is reached. Data communication can be performed in the communication area. Therefore, the effect that the possibility of communication can be greatly improved can be obtained.

[Explanation of Example]

FIG. 2 is a block diagram showing the structure of the article identification system according to one embodiment of the present invention. In this figure, the article identification system is a pallet 10a holding parts to be identified,
Are configured to be transported on a transport path 11, and each pallet 10a, 10b.
Is mounted directly. Further, a read / write head (hereinafter referred to as RW head) 13 for writing and reading data at a position facing the data carrier 12 and an ID controller 14 connected to the RW head 13 and controlling the operation thereof are provided. The RW head 13 and the ID controller 14 constitute the write / read control unit 6. The ID controller 14 is connected to a host computer 15.

As shown in the block diagram of FIG. 3, the ID controller 14 is provided with a microprocessor (CPU) 21 for controlling writing and reading of data to and from the data carrier 12 and a memory 22 for holding the system program and data. Further, an input / output interface 23 for inputting / outputting with the host computer 15 is provided. An encoding circuit 24 and a decoding circuit 25 for encoding data to be transmitted to the data carrier 12 are connected to the input / output terminals of the CPU 21. The RW head 13 has a modulation circuit 26 for modulating the output of the encoding circuit 24 and a transmission unit 27 driven by the output. The transmitting unit 27 transmits data to a data carrier by outputting a signal subjected to FSK modulation from a coil, for example. The received signal obtained from the data carrier is
The signal is supplied to a demodulation circuit 29 through 28. The demodulation circuit 29 demodulates this signal and supplies it to the decoding circuit 25.

Next, the configuration of the data carrier 12 will be described with reference to FIG. In FIG. 4, the transmission / reception section 31 is the RW head 13.
It receives and transmits a signal of a frequency emitted from the device, and the received output is provided to a demodulation circuit 32. The demodulation circuit 32 demodulates this signal and supplies its output to the decoding circuit 33. The decoding circuit 33 decodes the encoded data into an original signal and supplies the original signal to the control unit. Memory 35 memory 35 constituted by a static RAM or E ² PROM backed up by, for example, a battery 36 via the bus is connected to the control unit 34. The control unit 34 is a memory control unit 2 that controls to write or read data according to the command and data given from the ID controller 14,
The read data is converted into a serial signal and applied to the encoding circuit 37. The encoding circuit 37 encodes a given signal in the same manner as the encoding circuit 24 of the ID controller 14, and its output is supplied to the transmission / reception unit 31 via the modulation circuit 38. The transmission / reception unit 31 outputs signals by changing the resonance frequency of the resonance circuit as in the conventional example, for example, to the RW head.
It is given to the 13 side. Here, the transmission / reception unit 31, demodulation circuit 3
The modulation circuit 2 and the modulation circuit 38 demodulate the data of the command given from the ID unit, give the data to the memory control means, and constitute the data transmission means 3 for transmitting the read data.

Next, the operation of this embodiment will be described with reference to a flowchart. FIG. 5 is a flowchart showing the operation of the ID controller. When the operation is started, first, in step 41, reception of a command is waited for. The command is one of a read command and a write command for reading and writing data from the host computer 15 and an auto read and an auto write command for automatically repeating the same operation until a data carrier arrives. If a read command or an auto-read command is received among such commands, the process proceeds from step 42 to step 43 to decode the command. The decoding of the command is decoding of a read address, a read byte, and the like. Then, the process proceeds to step 45 to wait for a response from the data carrier 12, and if there is no error at the time of the response, sends a response after the read is completed to the host computer 15 and ends the process (step 46). If there is an error in step 45, the flow advances to step 47 to check whether the command is an auto read command. If it is not an auto read command, it is a normal read command, so the process proceeds to step 48, where a read error response is returned to the host computer 15, and the process is terminated. In step 47, if it is an auto-read command, it is checked whether or not there is an absence error. If it is an absent error, the process returns to step 44 to send a read command again to perform the same processing. In this manner, the read command is continuously transmitted at a predetermined cycle as in the conventional example until the data carrier 22 approaches. If there is no absent error, it is determined that a transmission error has occurred due to the influence of noise or the like even when the read / write head 13 has entered the unstable communication area or is in the stable area. 50). Then, the process proceeds to a step 51, wherein it is checked whether or not the counter has counted up to the predetermined number N, and if the number of retries N has not been reached, the process returns to the step 44 to repeat the same processing. When the number of retries N has been reached, the process proceeds to step 48, where a read / write error response is sent to the host computer, and the process is terminated.

Similarly, if the received command is a write command, the process proceeds from step 52 to step 53 to decode the write command. This decoding is decoding of a write address, write data, and the number of write bytes. Thereafter, the flow advances to step 54 to send a write command to the data carrier 12. Then, in step 55, it is checked whether or not the command has been executed normally from the data carrier 12, and if no error occurs, a write end response is sent to the host computer 15 to end the processing (step 56). If an error occurs, it is checked whether the command is an auto command in the case of a read auto command (step 57). If not, a write error response is sent to the host computer (step 58), and the process is terminated. If the command is an auto command, the flow advances to step 59 to check for an absence error. If the error is absent, the flow returns to step 54 to repeat the same processing. If the absence error has not occurred, the retry counter is incremented (step 60), and the routine proceeds to step 61, where it is checked whether this counter has reached the number of retries N and has counted up. If the number of retries N has not been reached, the process returns to step 54 to repeat the same processing. If the number of retries has been reached, the process proceeds to step 58, where a write error response is sent out and the process ends. If it is not a write command in step 52, the process proceeds to step 62, where an undefined error is transmitted, and the process returns to step 41.

As described above, according to the present invention, in the case of an auto command, the command is repeatedly sent even if there is an absent error, and if the error is not an absent error, the retry counter is incremented and the retry is repeated up to a predetermined number of times, so that the auto command is executed reliably. I can do it.
The number of retries N is the data carrier number as shown in FIG.
When 12 is fixed to the pallet 10 or the like passing through the transport path 11, it is preferable to determine it according to the transport speed of the transport path. Therefore, each time the transfer speed of the transfer line for data or the like is changed, the speed may be manually set. The output of the speedometer 70 for detecting the transfer speed is supplied to the ID controller, and the number of retries N is automatically determined based on the speed signal. You may make it set.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram showing the overall configuration of the present invention, and FIG.
FIG. 3 is a perspective view showing the overall configuration of the article identification system, FIG. 3 is a block diagram showing the configuration of the ID controller, FIG. 4 is a block diagram showing the configuration of the data carrier, and FIG. 5 is a flowchart showing the operation of the ID controller. FIG. 6 is an access flow diagram of a conventional identification system, and FIG. 7 is a schematic diagram showing a communication area between a conventional write / read control unit and a data carrier. 1,35 memory, 2 memory control means, 3,5 data transmission means, 4,12 data carrier, 6 write / read control unit, 13 read / write head, 14 … ID
Controller, 15 Host computer, 21 CPU, 3
4 ... Control unit

Claims (1)

(57) [Claims] A memory for holding data; a memory control means for controlling writing of data to the memory or reading of data from the memory; and demodulating an externally applied command and providing the demodulated command to the memory control means. A data carrier having data transmission means for transmitting the read data, and a data carrier attached to an article to be identified; and a data transmission means for transmitting data to the data carrier or receiving data transmitted from the data carrier. And a write / read control unit comprising: a write / read control unit that sends a command to a data carrier via the data transmission unit, and outputs a command when a data carrier absent error occurs. A repeat command is sent, and the data carrier is read / written by the write / read control unit. Article identification system access error occurring when located in unstable communication area in communication with the Tsu bets are characterized by having an automatic command sending means for sending said command to a predetermined number.