JP2021197628A - Data transmission device and data transmission method - Google Patents

Abstract

To provide a data transmission device capable of switching systems without data loss when communication of two systems with different bands is performed.SOLUTION: Each of a first wireless communication device 10A and a second wireless communication device 10B installed so as to be movable relative to each other includes: a first communication unit 11 including a first transmission unit 11T and a first reception unit 11R that wirelessly communicate in a first band; a second communication unit 12 including a second transmission unit 12T and a second reception unit 12R that wirelessly communicate in a second band; a communication control unit 15 that controls both the first communication unit and the second communication unit; a data input unit 13 that inputs transmission data; and a data output unit 14 that outputs reception data. The communication control unit on a transmitting side controls the transmission data input from the data input unit to be transmitted in parallel via the first transmission unit and the second transmission unit. The communication control unit on a receiving side is configured to output any one piece of pieces of reception data received in parallel via the first reception unit and the second reception unit from the data output unit.SELECTED DRAWING: Figure 4

Description

The present invention relates to a data transmission device and a data transmission method incorporated in a semiconductor device manufacturing facility or the like.

In a semiconductor device manufacturing facility, in order to automatically transport a semiconductor wafer between each manufacturing device, a wafer carrier device containing a plurality of semiconductor wafers mounted on a load port provided in each manufacturing device is transported. An automatic transfer device such as an OHT (Overhead Hoist Transfer), which is an unmanned transfer vehicle traveling on a ceiling (hereinafter referred to as a “transfer trolley”), is used.

A data transmission device is incorporated in such a transport trolley and a manufacturing device, and a wafer carrier device is transferred between the transport trolley and the manufacturing device based on control information exchanged via the data transmission device. As such a data transmission device, an 8-bit parallel optical data transmission device embodying the interlock sequence defined in the SEMI standard E84 is used.

In Patent Document 1, as such a data transmission device, bit information is modulated into a pulse signal by combining an arbitrary period and a pulse number set in advance, and is composed of an arbitrary number of bits and is predetermined between bits. An optical data transmission device for transmitting and receiving frame data in which a null period of a width is set is disclosed via a light emitting element and a light receiving element.

Further, Patent Document 2 proposes an optical data transmission device having a wireless communication function in case a communication error occurs in the optical data transmission device.

However, since it is configured to switch to wireless communication when a communication error occurs in optical data transmission, communication between them will be interrupted, and there will be problems that the wafer carrier device cannot be transferred smoothly, and optical data transmission. It is necessary to build hardware for both wireless communication and wireless communication, and there is also the problem that the equipment cost increases.

Patent Document 3 describes a radio signal transmission processing unit that transmits a radio carrier on which information to be transmitted is superimposed, which is modulated by a pulse position modulation method, and the transmission that is modulated by the pulse position modulation method. A base that modulates the information to be transmitted according to the optical signal transmission processing unit that transmits the optical carrier on which the information is superimposed and the pulse position modulation method common to the radio signal transmission processing unit and the optical signal transmission processing unit. A transmission device including a band processing unit, a radio signal reception processing unit that receives a radio carrier on which information to be received is superimposed, which is modulated by a pulse position modulation method, and a radio signal reception processing unit that is modulated by the pulse position modulation method. Further, the reception is performed according to the pulse position modulation method common to the optical signal reception processing unit that receives the optical carrier on which the information to be received is superimposed, the radio signal reception processing unit, and the optical signal reception processing unit. A communication device including a receiving device including a baseband processing unit that demolishes power information is disclosed.

In the communication device, the circuit configuration is simplified and the cost is reduced by configuring the baseband processing unit so that it can be shared.

Japanese Unexamined Patent Publication No. 2010-161731 Japanese Unexamined Patent Publication No. 2015-213318 Japanese Unexamined Patent Publication No. 2008-271500

However, even in the communication device described in Patent Document 3, the data received by both the optical signal reception processing unit and the wireless signal reception processing unit cannot be demodulated at the same time by the baseband processing unit, and the optical signal reception processing unit cannot be demodulated at the same time. If a reception error occurs in either one of the wireless signal reception processing units, the configuration is such that the other reception processing unit is switched to after that, so that the received data transmitted during the time required for switching cannot be received and disappears. The problem of doing is not solved.

This problem is not limited to the combination of optical communication using infrared light and wireless communication using high frequency as in Patent Documents 2 and 3, but also occurs when two systems having different bands are communicated.

An object of the present invention is to provide a data transmission device and a data transmission method capable of switching a system without data loss when two systems having different bands are communicated in view of the above-mentioned conventional problems. It is in.

In order to achieve this object, the first characteristic configuration of the data transmission device according to the present invention is a data transmission device composed of a first wireless communication device and a second wireless communication device installed so as to be relatively movable with each other. The first communication unit provided with the first transmission unit and the first reception unit for wireless communication in the first band in both the first wireless communication device and the second wireless communication device is different from the first band. A second communication unit including a second transmission unit and a second reception unit that perform wireless communication in the second band, a communication control unit that controls both the first communication unit and the second communication unit, and the communication control unit. A data input unit for inputting transmission data and a data output unit for outputting received data from the communication control unit are provided, and the communication control unit on the transmission side transmits the transmission data input from the data input unit to the first transmission. It is controlled to transmit in parallel via the unit and the second transmitting unit, and the communication control unit on the receiving side receives the received data received in parallel via the first receiving unit and the second receiving unit. The point is that either one is configured to be output from the data output unit.

The first wireless communication device and the second wireless communication device are each provided with a first communication unit and a second communication unit having different communication bands, and the communication control units provided in both of the first communication unit and the second communication unit are provided with each other. It is controlled to communicate with each other. In the wireless communication device on the transmitting side, the transmission data input via the data input unit is transmitted by the communication control unit via the first transmission unit provided in the first communication unit and the second transmission unit provided in the second communication unit. It is transmitted in parallel, and in the wireless communication device on the receiving side, the transmission data is received and communicated in parallel via the first receiving unit provided in the first communication unit and the second receiving unit provided in the second communication unit. Either one is output from the data output unit by the control unit. Even if a communication failure occurs in either the first communication unit or the second communication unit, the inconvenient state of loss of received data does not occur unless a communication failure occurs in the other.

In the second feature configuration, in addition to the first feature configuration described above, when the communication control unit transmits data, the transmission data input from the data input unit is transmitted to the first transmission unit. It is configured to repeatedly transmit data in the first cycle via the second transmission unit and repeatedly transmit data in a second cycle equal to or less than half the cycle of the first cycle via the second transmission unit, and the communication control unit receives data. In addition, either one of the received data received in the first cycle via the first receiving unit and the received data received in the second cycle via the second receiving unit is output as the data in the first cycle. The point is that it is configured to output from the unit.

In the wireless communication device on the transmitting side, the transmission data input from the data input unit is repeatedly transmitted from the first transmission unit in the first cycle, and is repeatedly transmitted from the second transmission unit in the second cycle. When there is no change in the transmission data, the same data is repeatedly transmitted from the first transmission unit in the first cycle, and the same data is repeatedly transmitted from the second transmission unit in the second cycle. Since the second cycle is set to a cycle equal to or less than half the cycle of the first cycle, the same transmission data is transmitted from the second transmission unit at least twice while the transmission data is transmitted once from the first transmission unit. Will be done. In the wireless communication device on the receiving side, the first receiving unit obtains the received data in the first cycle, and the second receiving unit obtains the received data in the second cycle. Therefore, the communication control unit obtains the received data of the first receiving unit. And the received data of the second receiving unit are selected and output from the data output unit in the first cycle, that is, in the longer cycle. If the communication cycle required as a product is set to the first cycle, communication redundancy can be ensured within the first cycle.

In the third feature configuration, in addition to the second feature configuration described above, the communication control unit is a data discrimination unit that determines the authenticity of the received data received by the first receiving unit and the second receiving unit. The point is that the latest received data determined to be true by the data discrimination unit is output from the data output unit.

By providing a data discrimination unit, the reliability of the received data can be guaranteed, and even if one of the received data is determined to be false by the data discrimination unit, the other received data determined to be true. Since the latest value of is adopted as the received data, it is possible to avoid a significant delay from the switching of the transmitted data to the switching of the received data.

In the fourth feature configuration, in addition to the third feature configuration described above, the communication control unit receives the received data via the first reception unit and determines that the received data is true by the data discrimination unit. 2 Regardless of the authenticity of the received data received by the receiving unit, the data output unit outputs the data, and when the data discriminating unit determines that the received data received via the first receiving unit is false, the second receiving unit The point is that the received data received via the data output unit and determined to be true by the data determination unit is output from the data output unit.

The received data received by the first receiving unit and determined to be true is preferentially output from the data output unit. When the received data received by the first receiving unit is determined to be false, the received data received by the second receiving unit and determined to be true is complementarily output. Therefore, the loss of received data can be avoided.

In the fifth feature configuration, in addition to the fourth feature configuration described above, the communication control unit cannot obtain true received data via the first receiving unit in the first cycle, and , If true received data cannot be obtained via the second receiver in the first cycle, the most recent true received data previously received via the first receiver or the second receiver. The point is that the received data of the above is configured to be output from the data output unit.

When true received data cannot be obtained by either the first receiving unit or the second receiving unit in the first cycle, the latest received data is the true received data received via the first receiving unit or the second receiving unit. Is output complementarily. Therefore, the loss of received data can be avoided.

In the sixth feature configuration, in addition to any of the third to fifth feature configurations described above, the communication control unit receives true reception data in both the first receiving unit and the second receiving unit. The point is that if the state that cannot be obtained continues for a predetermined number of times with the first cycle as a unit, it is determined as a communication error.

If a communication error occurs immediately when true reception data cannot be obtained by both the first receiving unit and the second receiving unit, the system incorporating the data transmission device may stop even if the normal recovery is subsequently performed. However, if the state in which true received data cannot be obtained returns to normal until it continues for a predetermined number of times in the first cycle as a unit, the system incorporating the data transmission device will not be stopped. Therefore, the limit to which the non-updatable state of the received data can be tolerated is set to a predetermined number of times in the first cycle as a unit.

The seventh feature configuration is that, in addition to the sixth feature configuration described above, the communication control unit includes a monitor display unit that displays the status when a communication error is determined.

By checking the display state of the monitor display unit, it is possible to easily determine what kind of state it is.

In the eighth feature configuration, in addition to any of the third to seventh feature configurations described above, the first band, which is the communication band of the first communication unit, is set as the optical communication band, and the above-mentioned Even if the second band, which is the communication band of the second communication unit, is set to the RF communication band, and the communication control unit cannot receive true received data via the first communication unit, the second communication unit When the true received data can be received via the above, the state signal to be output is maintained during the establishment of communication with the other party via the first communication unit.

When communication is established between the first communication unit on the receiving side and the first communication unit on the transmitting side that perform optical communication, the first communication unit on the receiving side switches the status signal to the on state, and when the communication is interrupted, the status signal. To switch to the off state. When the status signal of the first communication unit on the transmitting side is switched to the off state, the processing is interrupted due to a communication error. However, even if the true received data cannot be received via the first communication unit that performs optical communication, if the true reception data can be received via the second communication unit that performs RF (Radio Frequency) communication, it is received. Since the first communication unit on the side maintains the status signal, the processing is not interrupted due to a communication error.

In the ninth feature configuration, in addition to any of the third to eighth feature configurations described above, the communication control unit receives true via the first communication unit and / or the second communication unit. The point is that the storage unit is provided to hold the received data of the above for at least the first cycle.

For example, even if the received data received via the first communication unit is false, the true reception data received via the second communication unit in the first cycle corresponding to the received data is stored in the storage unit. Then, the true received data read from the storage unit in the next first cycle can be output from the data output unit. The same applies when the received data received via the second communication unit is false.

In the tenth feature configuration, in addition to any of the second to ninth feature configurations described above, the first communication unit is either or both of the first wireless communication device and the second wireless communication device. Connected to one side so as to be detachable, the communication control unit compares each received data received by the first receiving unit and the second receiving unit within the cycle of the first cycle, and each received data is different. The point is that it is configured to determine a communication error in some cases.

For example, when the first wireless communication device functions as a receiving side and the first communication unit is configured to be detachable from the first wireless communication device, the first communication unit inputs data to the first wireless communication device. If the authenticity of the received data cannot be verified by the communication control unit, the received data received by the first receiving unit and the second receiving unit are compared within the cycle of the first cycle, and each received data is obtained. If they are different, it can be determined as a communication error.

In the eleventh feature configuration, in addition to any of the second to tenth feature configurations described above, the communication control unit receives each received data received by the first receiving unit and the second receiving unit. When a comparison is made retroactively and there is a change in the received data in only one of them, the changed received data is output from the data output unit.

In the twelfth feature configuration, in addition to any of the second to eleventh feature configurations described above, the communication control unit receives data received by the first receiving unit and the second receiving unit. Is retroactively compared, and when each received data is continuously different a predetermined number of times in the first cycle as a unit, it is determined to be a failure.

The first characteristic configuration of the data transmission method according to the present invention is the data transmission method executed between the first wireless communication device and the second wireless communication device, which are installed so as to be relatively movable with each other. Both the wireless communication device and the second wireless communication device can execute a first communication step in which wireless communication is performed in the first band and a second communication step in which wireless communication is performed in a second band different from the first band. The wireless communication device on the transmitting side of the first wireless communication device and the second wireless communication device performs the first communication step and the second transmission communication step when transmission data is input from the outside. By executing in parallel, the same transmission data is transmitted to the other party, and the wireless communication device on the receiving side of the first wireless communication device and the second wireless communication device is the first communication step and the second communication device. The point is that the transmission communication step is executed in parallel and one of the received data is output to the outside as the received data.

In the second feature configuration, in addition to the first feature configuration described above, in the first communication step executed by the wireless communication device on the transmitting side, the transmission data is repeatedly transmitted in the first cycle, and the transmission data is repeatedly transmitted. The second communication step is configured to repeatedly transmit the transmission data in a second cycle of half a cycle or less of the first cycle, and the receiving side wireless communication device is configured to repeatedly transmit the transmission data in the first communication step. One of the received data received in one cycle and the received data received in the second cycle via the second communication step is configured to be output to the outside in the first cycle.

As described above, according to the present invention, it is possible to provide a data transmission device and a data transmission method capable of switching systems without data loss when communicating between two systems having different bands. It became so.

Explanatory drawing of manufacturing equipment for semiconductor devices incorporating data transmission equipment Explanatory diagram of data transmission / reception sequence between manufacturing equipment and OHT Explanatory diagram of operation accompanying data transmission / reception between manufacturing equipment and OHT (A) is a functional block configuration diagram of the data transmission device, (b) is an explanatory diagram of the data transmission device showing the connection mode of the wireless communication device on the transmitting side and the receiving side, and (c) is a diagram in which the first communication unit can be freely attached and detached. Explanatory drawing of the aspect configured in Waveform explanatory diagram of frame data transmitted and received by the first communication unit Timing chart of communication data normally exchanged by the data transmission device A comparative example is shown, and a timing chart of communication data when a communication error occurs and is exchanged only by the first communication unit of the data transmission device. A comparative example is shown, and the timing chart of communication data when a communication error occurs in the data transmission device. Timing chart of communication data when a communication error occurs in the data transmission device of the present invention Explanatory diagram showing a specific configuration example of a data transmission device (A) is an explanatory diagram of an application example of the data transmission device shown in FIG. 10, and (b) is an explanatory diagram of an application example of the data transmission device shown in FIG. (A) is an explanatory diagram of an application example of the data transmission device shown in FIG. 10, and (b) is an explanatory diagram of an application example of the data transmission device shown in FIG.

An embodiment of the data transmission device and the data transmission method according to the present invention will be described below.
[Example of a system in which a data transmission device is used]
As shown in FIG. 1, in a semiconductor device manufacturing facility, various manufacturing devices ME (ME1, ME2, ME3, ME4) for sequentially performing predetermined processing on semiconductor wafers are arranged along a passage PW. .. In order to automatically transport the semiconductor wafer W between the manufacturing apparatus MEs, a transport carriage OHT is provided so as to be able to travel along the traveling rail R installed in the upper space of the manufacturing apparatus ME, and is provided in each manufacturing apparatus ME. It is configured to transfer the wafer carrier device CR to and from the load port LP.

The transport carriage OHT has an elevating body 4 provided with a chuck mechanism 3 for gripping the wafer carrier device CR on a base 2 provided with a traveling mechanism 1 self-propelled along the traveling rail R in a predetermined elevating path. A lifting mechanism 5 for raising and lowering along the line is incorporated.

The elevating mechanism 5 rotationally drives the elevating body 4, a plurality of belts 6 having one end fixed to a predetermined position on the upper surface of the elevating body 4, and a take-up shaft to which the other ends of the belts 6 are fixed. A motor is provided, and the belt 6 is wound up or unwound by driving the elevating motor provided on the base 2, and the elevating body 4 is configured to be able to move up and down with respect to the base 2.

The chuck mechanism 3 includes a pair of claws 3A for gripping the gripped portion on the upper surface of the wafer carrier device CR, and the claws 3A are gripped by driving a gripping solenoid or a motor provided inside the elevating body 4. The wafer carrier device CR is configured to be gripped or opened by being in a holding posture or an opening posture.

Such a transport carriage OHT includes, for example, a system communication unit capable of communicating with a host computer via a communication interface incorporated in the traveling rail R, and travels to a predetermined manufacturing apparatus ME based on an instruction from the host computer. However, the wafer carrier device CR is configured to be exchanged with the manufacturing device ME.

In order to exchange the wafer carrier device CR between the carrier OHT and each manufacturing device ME, a data transmission device 10 that operates based on the SEMI E84-0200A interface standard is incorporated. The data transmission device 10 is composed of a first wireless communication device 10A provided on the OHT side of the transport carriage and a second wireless communication device 10B provided on the manufacturing device ME side.

The transport trolley OHT controls the traveling mechanism 1 to move to a predetermined manufacturing apparatus ME based on a command from the host computer via the system communication unit, and transmits / receives to / from the manufacturing apparatus ME via the data transmission apparatus 10. A control device that controls the elevating mechanism 5, the chuck mechanism 3, and the like based on the data is mounted.

[Explanation of data transmission device]
2 and 3 show the first radio communication device 10A provided on the carrier OHT on the active device side and the second radio provided on the manufacturing device ME on the passive device side based on the SEMI E84-0200A interface standard. The exchange of signals with and from the communication device 10B is shown. The data transmission device 10 of the present invention is configured by the first wireless communication device 10A and the second wireless communication device 10B.

When the carrier OHT reaches a predetermined position with respect to the manufacturing apparatus ME, the first wireless communication apparatus 10A outputs a CS-0 signal, selects a desired load port number, and outputs a VALUE signal indicating a communicable state.

When the second wireless communication device 10B that has detected the VALUE signal outputs the signal L-RQ indicating that the selected load port number is ready, the first wireless communication device 10A outputs the transfer request signal TR-RQ. .. When the second wireless communication device 10B that has received the transfer request signal TR-EQU outputs the transfer request acceptance signal READY, the first wireless communication device 10A outputs the transfer start signal BUSY and the wafer carrier from the carrier OHT. The device CR is transferred.

When the wafer carrier device CR is transferred to a fixed position, the signal L-RQ of the second wireless communication device 10B is turned off, and in response to this, the first wireless communication device 10A turns off the transfer start signal BUSY and transfers. The request signal TR-EQU is turned off, and the transfer end signal COMPT is output. The second wireless communication device 10B that received the transfer end signal COMPT turns off the transfer request acceptance signal READY, and then the first wireless communication device 10A turns off the transfer end signal COMPT and the VALUE signal to end the transfer operation. do.

As shown in FIG. 4A, the data transmission device 10 is a first wireless communication device 10A and a second wireless communication device installed so as to be relatively movable with each other as in the relationship between the transport carriage OHT and the manufacturing device ME. It is composed of 10B.

What is the first communication unit 11 provided with the first transmission unit 11T and the first reception unit 11R for wireless communication in the first band on both the first wireless communication device 10A and the second wireless communication device 10B, and the first band? A second communication unit 12 having a second transmission unit 12T and a second reception unit 12R that wirelessly communicate in different second bands, and a communication control unit 15 that controls both the first communication unit 11 and the second communication unit 12. , A data input unit 13 that inputs transmission data to the communication control unit 15, a data output unit 14 that outputs reception data from the communication control unit 15, and communication addresses of the first communication unit 11 and / or the second reception unit 12R, etc. A communication setting unit 16 for setting the communication conditions of the above is provided. The communication setting unit 16 is provided with a general-purpose serial communication port such as RS232C, and is configured so that communication conditions can be set from the outside via the serial communication port.

The parallel signals input / output by the data input unit 13 and the data output unit 14 are signals according to the SEMI E84-0200A interface standard described with reference to FIG. The data transmission device 10 is a device that converts parallel signals exchanged between the carrier OHT and the manufacturing device ME into two wireless signals of a first band and a second band and transmits / receives them.

The communication control unit 15 is composed of a logic circuit including a CPU and a memory, and transmits data input from the data input unit 13 in parallel via the first transmission unit 11T and the second transmission unit 12T. It is configured to control and output either one of the received data received in parallel via the first receiving unit 11R and the second receiving unit 12R from the data output unit.

More specifically, the communication control unit 15 has a transmission processing unit 15A and a first reception unit that pass parallel signals input from the data input unit 13 as transmission data to the first transmission unit 11T and the second transmission unit 12T, respectively. The first discriminating unit 15B for discriminating the authenticity of the received data received by the unit 11R, the second discriminating unit 15C for discriminating the authenticity of the received data received by the second receiving unit 12R, and the first discriminating unit 15B. The comparison unit 15D, the monitor display unit 15F, and the comparison unit 15D output the reception data determined by comparing the reception data obtained from the second discrimination unit 15C with the reception data obtained from the data output unit 14. When a reception error is detected, an error processing unit 15E for lighting and controlling the error display provided on the monitor display unit 15F is provided.

In the first communication unit 11, the first band, which is the communication band, is set as the optical communication band, and in the second communication unit 12, the second band, which is the communication band, is set as the RF (Radio Frequency) communication band. Has been done.

The first transmission unit 11T includes a modulation circuit that modulates transmission data, which is a baseband signal, into a pulse signal of a predetermined frame data, and an infrared LED, which is a light emitting element that outputs a pulse signal modulated by the modulation circuit. The first receiving unit 11R is composed of a photodiode, which is a light receiving element that receives an optical pulse signal, and a pulse signal, which is frame data that is received by the photodiode and converted into an electric signal, as a baseband signal. It is equipped with a demodulation circuit that demodulates.

As shown in FIG. 5, the frame data is composed of a start bit STA indicating the beginning of the frame, a plurality of data bits D, a parity bit P indicating the parity of the data bit D, and a stop bit STP indicating the end of the frame. Has been done.

Each bit information represented by 0 or 1 is defined by a combination of two types of pulse periods and two types of pulse numbers.

A set of the above-mentioned unique pulse period and number of pulses is defined for each of the start bit STA, the stop bit STP, the data bit D 0, the data bit D 1, and the parity bit P.

Further, a null period NP of a predetermined time is set during the pulse output period SP constituting each bit, that is, between each bit. Hereinafter, a series of pulse signals detected in the pulse output period SP will also be referred to as a bit group.

That is, the bit information is modulated into a pulse signal that is a combination of a preset arbitrary period and the number of pulses, and the frame data composed of an arbitrary number of bits and having a null period of a predetermined width between the bits is the first. It is transmitted and received between the communication units 11.

The period indicating the bit information, the number of pulses and their combination, the length of the null period, and the number of data bits included in the frame data are arbitrarily set according to the system. Further, although not described in detail in the present specification, other than the above-mentioned frame data, another signal for hand shake is exchanged between the first communication unit 11 via another light emitting element and a light receiving element. It may be a thing. Further, the above-mentioned frame data may be configured to include signals other than the parallel signal input from the data input unit.

The second communication unit 12 is an RF wireless communication unit for Wi-Fi compliant with the standard IEEE802.11 capable of wireless transmission in the 5 GHz band and 2.4 GHz band (WiFi is a registered trademark of Wi-Fi Alliance). The second transmission unit 12T generates a frame data from transmission data which is a baseband signal and modulates it into a radio signal of 5 GHz band and 2.4 GHz band, and a frame data modulated by the digital modulation circuit. The second receiving unit 12R is configured to include a transmitting antenna for output, and includes a receiving antenna for receiving a high-frequency signal and a digital demodulator circuit for converting frame data received by the receiving antenna into a baseband signal. Since the configuration of the RF wireless communication unit based on 802.11 is well known, detailed description thereof will be omitted.

As shown in FIG. 6, the communication control unit 15 repeatedly transmits the frame data in the first cycle T1 via the first transmission unit 11T, and repeats the frame data in the second cycle T2 via the second transmission unit 12T. It is configured to send. In this embodiment, the first period T1 is 20 msec. The second period T2 is set to 3.3 msec. Is set to. Therefore, basically, the first receiving unit 11R receives the data in the first cycle T1, and the second receiving unit 12R receives the data in the second cycle T2.

Each communication control unit 15 is configured to output a "GO" signal as a signal for notifying the connected device of the communication state. That is, the "GO" signal is started up in a state where communication with the other party is established, and the "GO" signal is turned off when the communication is not restored within a predetermined number of retries.

In the following FIGS. 6 to 9, the one-way transmission / reception operation of half-duplex communication between the first wireless communication device and the second wireless communication device is simplified and displayed. During the blank period in the cycle of frame data from the transmitting side to the receiving side, transmission / reception is performed in other directions (not shown).

Repeatedly transmitted in the first cycle T1 via the first transmitting unit 11T, and repeatedly transmitted in the second cycle T2 having a relatively short time of half a cycle or less of the first cycle T1 via the second transmitting unit 12T. The specific values of the first period T1 and the second period T2 are not limited as long as they are configured.

Then, the comparison unit 15D provided in the communication control unit 15 receives the received data received in the first cycle T1 via the first receiving unit 11R and the received data received in the second cycle T2 via the second receiving unit 12R. In comparison, one of them is output from the data output unit 14 in the first cycle T1.

As shown in FIG. 6, when only IN1 of the 8-bit parallel signals IN1 to IN8 indicates "1", one frame of data representing the binary data 000000001B is repeatedly repeated from the first transmission unit 11T in the period T1. It is transmitted and repeatedly transmitted from the second transmission unit 12T in the cycle T2.

In response to these, one frame of data representing the binary data 00000001B is repeatedly and repeatedly received by the first receiving unit 11R in the cycle T1 and repeatedly received by the second receiving unit 12R in the cycle T2.

At least, the 8-bit parallel signals IN1 to IN8 have the shortest signal value of the 8-bit parallel signals IN1 to IN8 so that the signal value does not change during the time 2T1 which is twice the period T1. It is set to a value equal to or greater than 1/2 of the signal switching cycle. In the example of FIG. 6, since the data is always normally received by the first receiving unit 11R, the data received by the first receiving unit 11R is output from the data output unit 14.

The first discriminating unit 15B and the second discriminating unit 15C shown in FIG. 4A constitute a data discriminating unit that discriminates the authenticity of the received data received by the first receiving unit 11R and the second receiving unit 12R. The latest received data determined to be true by the data discrimination units 15B and 15C is output from the data output unit 14 via the comparison unit 15D.

The data discrimination units 15B and 15C determine whether or not the frame data data received by the first reception unit 11R and the second reception unit 12R are appropriate data, respectively. Specifically, it is determined whether or not the data is appropriate based on whether or not the data length, header, footer, parity, CRC, and the like of the frame data are appropriate. Since these discriminations are performed on the frame data before the baseband signal is extracted, some of the functions of the data discrimination units 15B and 15C may be provided in the first receiving unit 11R and the second receiving unit 12R. be.

The reliability of the received data can be guaranteed by the data discrimination units 15B and 15C, and even if one of the received data is determined to be false by the data discrimination units 15B and 15C, the comparison unit 15D is true. The latest value of the other received data determined is adopted as the received data. The comparison unit 15D is provided with a storage unit that functions as a data buffer, and is configured to be able to store received data having a predetermined cycle determined to be normal.

For example, even if the received data received via the first communication unit 11 is false, the true reception data received via the second communication unit 12 in the first cycle T1 corresponding to the received data is stored in the storage unit. By storing the data, the true received data read from the storage unit can be output from the data output unit in the next first cycle T1.

The comparison unit 15D provided in the communication control unit 15 receives the received data via the first receiving unit 11R and determines that the data is true by the data discrimination unit 15B, regardless of whether the received data received by the second receiving unit 12R is true or false. When the data output unit 14 outputs the data and the received data received via the first reception unit 11R is determined to be false by the data discrimination unit 15B, the data is received via the second reception unit 12R and is determined to be true by the data discrimination unit 15C. The received data is configured to be output from the data output unit 14.

The received data received by the first receiving unit 11R and determined to be true is preferentially output from the data output unit. When the received data received by the first receiving unit 11R is determined to be false, the received data received by the second receiving unit 12R and determined to be true is output in a complementary manner. Therefore, the loss of received data can be avoided.

Further, the communication control unit 15 cannot obtain true reception data via the first reception unit 11R in the first cycle T1, and true reception via the second reception unit 12R in the first cycle T1. When the data cannot be obtained, the data output unit 14 is configured to output the latest received data as the true received data previously received via the first receiving unit 11R.

When true reception data cannot be obtained by either the first reception unit 11R or the second reception unit 12R in the first cycle T1, the latest reception data is the true reception data received via the first reception unit 11R. It is output complementarily. Therefore, the loss of received data can be avoided.

The communication control unit 15 is configured to determine a communication error when the state in which true reception data cannot be obtained by both the first reception unit 11R and the second reception unit 12R continues for a predetermined number of times in the first cycle as a unit. ing.

If true reception data cannot be obtained by both the first receiving unit 11R and the second receiving unit 12R and an immediate communication error occurs, the system incorporating the data transmission device 10 may stop even if the normal recovery occurs thereafter. There is.

However, if the state in which true received data cannot be obtained returns to normal until the first cycle T1 continues for a predetermined number of times, the system incorporating the data transmission device 10 will not be stopped. Therefore, the limit to which the non-updatable state of the received data can be tolerated is set to a predetermined number of times in the first cycle as a unit. Specifically, it is set in the range of 3 to 5 times with the first period T1 as a unit, but it is not limited to such a value.

As a comparative example, FIG. 7 shows signal timing charts of the first and second wireless communication devices 10A and 10B having only the first communication unit 11 and not the second communication unit 12. Basically, it operates in the same manner as the first and second wireless communication devices 10A and 10B provided with the second communication unit 12.

When communication is established before time t1 and the communication is interrupted and the status signal is turned off from the state in which the "GO" signal, which is a status signal indicating that fact, is turned on by the communication control unit 15 on the receiving side. , The normal received data immediately before that is maintained and output (indicated as "retry" in FIG. 7).

The communication control unit 15 or the first reception unit 11R is configured to restart the monitoring timer each time a normal reception is performed, and execute an abnormality determination process for determining that reception could not be performed when the monitoring timer detects a timeout. .. That is, it is configured to determine the communication error by both the error determination of the frame data executed by the data determination units 15B and 15C and the above-mentioned abnormality determination process.

Even if a communication error occurs at time t2, the status signal is maintained until the first cycle T1 following the first cycle T1 to which the time t2 belongs elapses, and the latest received data normally received is the next. It is configured to output during the first period T1 of.

If the communication error continues to occur even at time t3, the communication control unit 15 turns off the status signal. After that, when it is normally received at time t6, the status signal is turned on and communication is continued. In this example, if communication errors occur continuously after the time t2, the communication is interrupted and the received data is interrupted.

As another comparative example, FIG. 8 includes a first communication unit 11 and a second communication unit 12, and transmits data transmitted from the wireless communication device 10A on the transmitting side in parallel from the first transmission unit 11T and the second transmission unit 12T. An example of switching to reception of the second receiving unit 12R when a communication error occurs continuously in the first receiving unit 11R in the wireless communication device 10B on the receiving side is shown. If communication errors occur continuously, the status signal is turned off.

In this example, the second receiving unit 12R is not operating and the second receiving unit 12R is operating at time t4 until a communication error occurs in the first receiving unit 11R continuously at times t2 and t3. Even so, the received data will be lost in the first cycle T1 to which the time t4 belongs, and a time loss will occur due to the switching of reception.

As shown in FIG. 9, according to the data transmission device 10 according to the present invention, the reception side while transmitting the transmission data from the transmission side wireless communication device 10A in parallel from the first transmission unit 11T and the second transmission unit 12T. Since the wireless communication device 10B of the above is receiving data in parallel by the first receiving unit 11R and the second receiving unit 12R, a communication error occurs continuously in the first receiving unit 11R at times t2, t3, t4, and t5. However, since it is normally received by the second receiving unit 12R, if either the first receiving unit 11R or the second receiving unit 12R is normally received during the first cycle T1, the received data is received. Will not be missing. Then, the latest received data normally received in each of the first cycle T1 is output in the next first cycle T1.

Then, even if the communication control unit 15 cannot receive the true reception data via the first communication unit 11, if the communication control unit 15 can receive the true reception data via the second communication unit 12, the first communication unit 11 It is configured to maintain a status signal that is output during the establishment of communication with the other party via.

As described above, when communication is established between the first communication unit 11 on the receiving side and the first communication unit 11 on the transmitting side that perform optical communication, the first communication unit 11 on the receiving side turns on the status signal. When switching and communication is interrupted, the status signal is switched to the off status. When the status signal of the first communication unit 11 on the transmitting side is switched to the off state, the processing is interrupted due to a communication error.

However, even if the true received data cannot be received via the first communication unit 11 that performs optical communication, if the true reception data can be received via the second communication unit 12 that performs RF communication, the receiving side Since the first communication unit 11 maintains the status signal, the processing is not interrupted due to a communication error.

4 (b) and 4 (c) show the configuration of the data transmission device 10 shown in FIG. 4 (a). In FIG. 4B, the first wireless communication unit 10A and the second wireless communication unit 10B shown in FIG. 4A are optically communicated via the first communication unit 11 and via the second communication unit 12. A mode of wireless communication is shown. The communicable distance of optical communication is set to about 1 m, and the communicable distance of wireless communication is set to about 10 m.

In FIG. 4C, the first communication unit 11 provided in each of the first wireless communication unit 10A and the second wireless communication unit 10B can be freely attached to and detached from the main body including the second communication unit 12 and the like. The configured embodiments are shown. Since the first communication unit 11 is configured to be freely removable with respect to the main body, the degree of freedom of installation is increased. That is, it becomes easy to align the optical axes of the first communication units 11 with each other at the time of installation.

In a configuration in which the first communication unit 11 can be freely attached to and detached from the main body, it may be difficult for the communication control unit 15 to detect an error in the received data in the first communication unit 11. There is a possibility that the received data input from the first communication unit 11 is maintained as the data before the first cycle. However, even in such a case, the communication control unit 15 compares the received data received by the first receiving unit 11R and the second receiving unit 12R within the cycle of the first cycle T1, and the received data are different. Can be configured to determine a communication error. It should be noted that such a determination process can be adopted even when the first communication unit 11 is integrally configured with the main body.

Similarly, the communication control unit 15 retroactively compares each received data received by the first receiving unit 11R and the second receiving unit 12R, and if there is a change in the received data in only one of them, the changed reception. The data may be configured to be output from the data output unit.

It is determined that the received data does not change because a communication error has occurred or a failure has occurred.

The communication control unit 15 retroactively compares the received data received by the first receiving unit 11R and the second receiving unit 12R, and when the received data are continuously different for a predetermined number of times in the first cycle as a unit. It may be configured to be judged as a failure. Basically, the same received data should be received, but if the first cycle is continuously different for a predetermined number of times, there is a possibility that a failure has occurred in any of the receiving units 11R and 12R.

As described above, the data transmission method according to the present invention is a data transmission method executed between the first wireless communication device and the second wireless communication device installed so as to be relatively movable with each other, and is the first wireless. Both the communication device and the second wireless communication device are configured to be able to execute a first communication step in which wireless communication is performed in the first band and a second communication step in which wireless communication is performed in a second band different from the first band. , Of the first wireless communication device and the second wireless communication device, the wireless communication device on the transmitting side executes the first communication step and the second transmission communication step in parallel when transmission data is input from the outside. , The same transmission data is transmitted to the other party, and the wireless communication device on the receiving side of the first wireless communication device and the second wireless communication device executes the first communication step and the second transmission communication step in parallel. It is configured to output one of the received data as received data to the outside. The term “external” refers to a device to which the first wireless communication device or the second wireless communication device is connected, for example, the above-mentioned manufacturing device ME or transport trolley OHT.

Further, the first communication step executed by the wireless communication device on the transmitting side repeatedly transmits the transmission data in the first cycle, and the second communication step transmits the transmission data in the second cycle less than half the cycle of the first cycle. The wireless communication device on the receiving side is configured to repeatedly transmit, and either the received data received in the first cycle via the first communication step or the received data received in the second cycle via the second communication step. One is configured to be output to the outside in the first cycle.

The first wireless communication device and the second wireless communication device include a data discrimination step for discriminating the authenticity of the received data received in the first communication step and the second communication step, and are the latest to determine the truth in the data discrimination step. It is configured to output the received data of.

Then, the communication control unit outputs the received data received in the first communication step and determined to be true in the data determination step to the outside regardless of the authenticity of the received data received in the second communication step, and the first communication is performed. When the received data received in the step is determined to be false in the data determination step, the received data received in the second communication step and determined to be true in the data determination step is configured to be output to the outside.

Further, the first wireless communication device and the second wireless communication device cannot obtain true received data in the first cycle in the first communication step, and are true in the first cycle in the second communication step. When the received data of the above cannot be obtained, the true received data previously received through the first communication step is configured to output the immediately preceding received data to the outside.

Hereinafter, other embodiments will be described.
FIG. 10 illustrates specific configurations of the first wireless communication device 10A and the second wireless communication device 10B constituting the data transmission device 10.

A CPU that mainly functions as a communication control unit 15, an RF communication unit that functions as a second communication unit 12, an optical communication unit that functions as a first communication unit 11, an I / O interface that is a serial / parallel conversion circuit, and an Ethernet conversion circuit. PHY, RS232C driver that functions as a communication setting unit 16, FRAM that is a non-volatile memory element that stores important data such as communication setting data, received data, parallel input / output data, and failure data (FRAM is a registered trademark). And so on.

10-bit parallel data is input via the D-SUB connector 21, and 9-bit parallel data is output. The 10-bit parallel data includes transmission data, and the 9-bit parallel data includes reception data. Serial data is exchanged between the CPU and the I / O interface, and parallel data is exchanged via the D-SUB connector 21.

The RS232C signal is input / output to the RS232C driver via the D-SUB connector 21. Further, a DC24V power supply line is connected. The DC24V is converted into DC12V, which is the power supply for the power system, and DC3.3V, which is the power supply for the control system, by the DC / DC converter.

An Ethernet cable is connected to the PHY via the connector RJ-45, and data is exchanged with the CPU via the PHY. Further, the optical communication unit functioning as the first communication unit 11 is connected to the RS485 driver via the connector RJ-11, and data is exchanged with the CPU via the RS485 driver.

Such a data transmission device 10 is configured to be operable in a mode other than the above-mentioned operation mode.
As shown in FIG. 11A, if the optical communication unit functioning as the first communication unit 11 is removed, the communication address or the communication address can be obtained via the RS-232C or the Ethernet (ETHERNET / Ethernet is a registered trademark of Fuji Xerox Co., Ltd.) interface. By setting communication conditions such as communication channels, for example, wireless communication of 8-bit parallel data using RF communication via the second communication unit 12, and serial communication of 8-bit parallel data and RS-232C or Ethernet can be performed. It can be used for dual communication.

As shown in FIG. 11B, by setting communication conditions such as a communication address and a communication channel via the RS-232C or Ethernet interface, it can be used for wireless communication of data on the RS-232C or Ethernet. ..

As shown in FIG. 12 (a), while transmitting and receiving 8-bit parallel data using the optical communication unit functioning as the first communication unit 11, communication addresses, communication channels, and the like are transmitted and received via RS-232C or Ethernet interface. By setting the communication conditions, for example, the serial data of RS-232C or Ethernet can be RF-communicated via the second communication unit 12. That is, two systems of data from different data sources can be transmitted and received independently.

As shown in FIG. 12B, while transmitting and receiving 8-bit parallel data via an optical communication unit functioning as the first communication unit 11, RF communication with a tablet computer or the like via the second communication unit 12 is performed. By doing so, the log of the data transmitted / received by the first communication unit 11 can be displayed in real time on the tablet computer.

That is, if the data transmission device 10 is configured as shown in FIG. 10, it can be used for multiple purposes. In order to operate according to the purpose, the communication control unit 15 may be set via the communication interface of RS-232C.

All of the above-described embodiments are merely one aspect of the present invention, and the scope of the present invention is not limited by the description thereof, and the specific configuration of each part is appropriately changed within the range in which the action and effect according to the present invention are exhibited. Needless to say, you can do it.

INDUSTRIAL APPLICABILITY The present invention can be widely applied as a data transmission device capable of switching systems without data loss when communicating between two systems having different bands.

10: Data transmission device 10A: 1st wireless communication device 10B: 2nd wireless communication device 11: 1st communication unit 11T: 1st transmission unit 11R: 1st reception unit 12: 2nd communication unit 12T: 2nd transmission unit 12R : Second receiving unit 13: Data input unit 14: Data output unit 15: Communication control unit 16: Communication setting unit

Claims (14)

It is a data transmission device composed of a first wireless communication device and a second wireless communication device installed so as to be relatively movable with each other.
A first communication unit having a first transmission unit and a first reception unit for wireless communication in the first band in both the first wireless communication device and the second wireless communication device, and a first communication unit different from the first band. The communication control unit includes a second communication unit having a second transmission unit and a second reception unit that perform wireless communication in two bands, a communication control unit that controls both the first communication unit and the second communication unit, and the communication control unit. It is equipped with a data input unit for inputting transmission data and a data output unit for outputting reception data from the communication control unit.
The communication control unit on the transmitting side controls the transmission data input from the data input unit to be transmitted in parallel via the first transmission unit and the second transmission unit.
The communication control unit on the receiving side is a data transmission device configured to output either one of the received data received in parallel via the first receiving unit and the second receiving unit from the data output unit. .. When transmitting data, the communication control unit repeatedly transmits the transmission data input from the data input unit in the first cycle via the first transmission unit, and the communication control unit repeatedly transmits the transmission data via the second transmission unit. It is configured to be repeatedly transmitted in the second cycle, which is less than half the cycle of the first cycle.
When the communication control unit receives data, either the received data received in the first cycle via the first receiving unit or the received data received in the second cycle via the second receiving unit. The data transmission device according to claim 1, wherein one of them is configured to be output from the data output unit in the first cycle. The communication control unit includes a data discrimination unit for discriminating the authenticity of the received data received by the first receiving unit and the second receiving unit, and the latest received data determined to be true by the data discriminating unit is the data. The data transmission device according to claim 2, which is configured to output from an output unit. The communication control unit receives received data via the first receiving unit and determines that the data is true from the data output unit regardless of whether the received data received by the second receiving unit is true or false. When the data discriminating unit determines that the received data that has been output and received via the first receiving unit is false, the received data received via the second receiving unit and determined to be true by the data discriminating unit is the data. The data transmission device according to claim 3, which is configured to output from an output unit. The communication control unit cannot obtain true received data via the first receiving unit in the first cycle, and receives true received data via the second receiving unit in the first cycle. A claim configured to output the most recent received data from the data output unit, which is the true received data previously received via the first receiver or the second receiver when it cannot be obtained. 4. The data transmission device according to 4. The communication control unit is configured to determine a communication error when the state in which true reception data cannot be obtained by both the first receiving unit and the second receiving unit continues for a predetermined number of times in the first cycle as a unit. The data transmission device according to any one of claims 3 to 5. The data transmission device according to claim 6, wherein the communication control unit includes a monitor display unit that displays a state when a communication error is determined. The first band, which is the communication band of the first communication unit, is set to the optical communication band, and the second band, which is the communication band of the second communication unit, is set to the RF communication band.
Even if the communication control unit cannot receive the true received data via the first communication unit, if the communication control unit can receive the true reception data via the second communication unit, the communication control unit goes through the first communication unit. The data transmission device according to any one of claims 3 to 7, which is configured to maintain a status signal to be output during establishment of communication with the other party. 3. 8. The communication control unit includes a storage unit that retains true received data received via the first communication unit and / or the second communication unit for at least the first cycle. The data transmission device according to any one. The first communication unit is detachably connected to both or one of the first wireless communication device and the second wireless communication device.
The communication control unit compares each received data received by the first receiving unit and the second receiving unit within the cycle of the first cycle, and determines that a communication error occurs when the received data are different. The data transmission device according to any one of claims 2 to 9, which is configured. The communication control unit retroactively compares each received data received by the first receiving unit and the second receiving unit, and if there is a change in the received data in only one of them, the changed received data is compared. The data transmission device according to any one of claims 2 to 10, which is output from a data output unit. The communication control unit retroactively compares each received data received by the first receiving unit and the second receiving unit, and when each received data is continuously different a predetermined number of times in the first cycle as a unit. The data transmission device according to any one of claims 2 to 11, which is configured to be determined to be a failure. It is a data transmission method executed between a first wireless communication device and a second wireless communication device installed so as to be relatively movable with each other.
A first communication step in which both the first wireless communication device and the second wireless communication device perform wireless communication in the first band, and a second communication step in which wireless communication is performed in a second band different from the first band. Is configured to be viable and
Of the first wireless communication device and the second wireless communication device, the transmission side wireless communication device executes the first communication step and the second transmission communication step in parallel when transmission data is input from the outside. By doing so, the same transmission data is sent to the other party,
Of the first wireless communication device and the second wireless communication device, the wireless communication device on the receiving side executes the first communication step and the second transmission communication step in parallel to receive either one of the received data. A data transmission method that is configured to be output externally as received data. The first communication step executed by the wireless communication device on the transmitting side repeatedly transmits the transmission data in the first cycle, and the second communication step transmits the transmission data in half a cycle or less of the first cycle. It is configured to transmit repeatedly in the second cycle,
The wireless communication device on the receiving side receives either one of the received data received in the first cycle via the first communication step and the received data received in the second cycle via the second communication step. The data transmission method according to claim 13, which is configured to output to the outside in the first cycle.

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