JP2011151484A - Optical communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication device that surely executes transmission/reception even if erroneous setting is performed so that both optical data transmitters are set in transmission standby modes. <P>SOLUTION: The optical communication device is configured to execute half duplex communication between a fixed facility and a moving facility, respectively, in which an optical data transmitter is installed. The optical data transmitter includes a transmitting part that modulates a transmission signal into a pulse-like optical signal so as to output the pulse-like optical signal, and a receiving part that receives the pulse-like optical signal so as to demodulate the pulse-like optical signal into a received signal. Each optical data transmitter also includes a retransmission control part that repeats retransmission processing for outputting an optical signal from the transmitting part at a prescribed retransmission time interval when a response to the optical signal outputted from the transmitting part is not confirmed in the receiving part. The retransmission control part provided in one optical data transmitter is set so as to repeat the retransmission processing at a retransmission time interval T2 longer than a retransmission time interval T1 by the retransmission control part provided in the other optical data transmitter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical data transmission apparatus including a transmission unit that modulates a transmission signal into a pulsed optical signal and outputs the signal, and a reception unit that receives the pulsed optical signal and demodulates it into a reception signal. The present invention relates to an optical communication device that is installed in a mobile facility and performs half-duplex communication between the fixed facility and the mobile facility, and an optical data transmission device used in the optical communication device.

  In a semiconductor device manufacturing facility, in order to automatically transfer a semiconductor wafer between manufacturing apparatuses, a wafer carrier apparatus containing a plurality of semiconductor wafers placed on a load port provided in each manufacturing apparatus is transferred. A transport cart is used.

  An optical data transmission device is incorporated in such a transport cart and a manufacturing apparatus, and a wafer carrier device is transferred between the transport cart and the manufacturing apparatus based on control information exchanged via the optical data transmission device. That is, each manufacturing apparatus is a fixed facility, and the transport cart is a moving facility.

  As described in Patent Document 1, the optical data transmission apparatus modulates bit information into a pulse signal sequence that combines two types of preset periods and two types of pulse numbers, and uses arbitrary bits. Tens of msec. In which a null period of a predetermined width is set between bits. The frame data is transmitted / received via the light emitting element and the light receiving element.

  The optical data transmission device outputs an optical signal from the transmitting unit on its own device side in order to avoid erroneous reception of an optical signal output from the transmitting unit on its own device side as stray light received by the receiving unit on its own device side. During this time, reception of the optical signal is prohibited at the receiving unit on the own device side, so it is not possible to perform full-duplex communication with the optical data transmission device on the other side, and it is configured to perform half-duplex communication. ing.

  When the optical data transmission device receives an optical signal from the counterpart optical data transmission device at the reception unit, a reception standby mode for transmitting an optical signal from the transmission unit to the counterpart optical data transmission device in response thereto; Before receiving the optical signal from the other party's optical data transmission device at the receiving unit, set the mode to one of the transmission priority modes for transmitting the optical signal from the own unit's transmission unit to the other side's optical data transmission device A mode setting unit is provided.

  The optical data transmission apparatus set in the transmission priority mode outputs an optical signal from the transmission unit to the counterpart optical data transmission apparatus when a communication permission signal is input from the outside, and the counterpart optical data transmission apparatus When the optical signal output in response is received by the receiving unit, handshaking is established, and then half-duplex communication is performed in both sides.

  When a communication permission signal is input from the outside, the optical data transmission device set to the reception standby mode waits until the receiving unit receives the optical signal output from the other optical data transmission device, and the optical signal In response to this, a handshake is established by outputting an optical signal from the transmission unit to the optical data transmission apparatus on the other side, and thereafter half duplex communication is performed on both sides.

  Each optical data transmission device outputs an optical signal from the transmission unit to the optical data transmission device on the other side, and receives the optical signal output in response to the optical data transmission device on the other side at the reception unit. In the meantime, a retransmission control unit that repeats retransmission processing for outputting an optical signal from the transmission unit at a predetermined retransmission time interval is provided. The retransmission control unit is configured to operate only when the optical data transmission apparatus is set to the transmission priority mode.

  When half duplex communication is performed with a pair of optical data transmission apparatuses, one optical data transmission apparatus needs to be set to the transmission priority mode, and the other optical data transmission apparatus needs to be set to the reception standby mode.

Japanese Patent No. 4372830

  However, if both optical data transmission devices are set incorrectly in the transmission priority mode and a communication permission signal is input to both optical data transmission devices, and transmission is performed almost simultaneously, There is a problem that both retransmission control units operate almost simultaneously and are in a state in which optical signals are output synchronously at the same retransmission time interval, and the communication failure state continues.

  In such a case, the mode setting by the mode setting unit is changed from the transmission priority mode to the reception standby mode for one side of many optical data transmission devices installed in many fixed facilities and mobile facilities. Although it is necessary to change, it was a very complicated and time-consuming operation.

  In view of the above-described conventional problems, an object of the present invention is an optical communication apparatus that can reliably transmit and receive even when both optical data transmission apparatuses are set erroneously such that both are set to the transmission priority mode. And providing an optical data transmission device.

  In order to achieve this object, the first characteristic configuration of the optical communication apparatus according to the present invention is to modulate a transmission signal into a pulsed optical signal and output it as described in claim 1 of the claims. An optical data transmission device including a transmission unit and a reception unit that receives a pulsed optical signal and demodulates it into a reception signal is installed in each of the fixed equipment and the mobile equipment. An optical communication device that performs multiple communication, wherein each optical data transmission device transmits an optical signal from the transmission unit at a predetermined retransmission time interval when a response to the optical signal output from the transmission unit is not confirmed by the reception unit. A retransmission control unit that repeats the retransmission processing to be output, and the retransmission control unit provided in one optical data transmission apparatus retransmits at a retransmission time interval longer than the retransmission time interval by the retransmission control unit provided in the other optical data transmission apparatus Repeat the process There is the point that has been set to.

  According to the above configuration, even if the optical signal is retransmitted from each transmission unit by both retransmission control units of the optical data transmission apparatus installed in both the fixed facility and the mobile facility, Since the retransmission control unit provided in the data transmission device repeats the retransmission process at a retransmission time interval longer than the retransmission time interval by the retransmission control unit provided in the other optical data transmission device, the transmission unit from one optical data transmission device Until the optical signal is retransmitted, the opportunity to receive the optical signal retransmitted from the transmission unit of the other optical data transmission apparatus at the reception unit of the one optical data transmission apparatus can be secured, so that You can now handshake.

  As described in claim 2, the second characteristic configuration includes the retransmission control unit provided in one optical data transmission apparatus in addition to the first characteristic configuration described above until the number of retransmissions reaches a predetermined number. In the meantime, the retransmission processing is set to be repeated at a retransmission time interval longer than the retransmission time interval by the retransmission control unit provided in the other optical data transmission apparatus.

  At least until the number of retransmissions reaches a predetermined number, the optical signal retransmitted from the transmission unit of the other optical data transmission apparatus is transmitted from one transmission unit of the other optical data transmission apparatus to one of the optical data transmission apparatuses. An opportunity to be received by the receiving unit of the optical data transmission apparatus can be secured, and the handshake can be surely performed.

  In the third feature configuration, in addition to the first feature configuration described above, the retransmission control unit provided in one optical data transmission device is provided in the other optical data transmission device. Even if the retransmission processing is repeated a predetermined number of times at a retransmission time interval equal to the retransmission time interval by the retransmission control unit, when the response to the optical signal output from the transmission unit is not confirmed by the reception unit, the other optical data transmission device is provided. The retransmission control unit is set to repeat retransmission processing at a retransmission time interval longer than the retransmission time interval.

  According to the above configuration, the retransmission control unit provided in one optical data transmission apparatus repeats the retransmission process a predetermined number of times at a retransmission time interval equal to the retransmission time interval by the retransmission control unit provided in the other optical data transmission apparatus. If the response to the optical signal output from the transmission unit is not confirmed by the reception unit, it is estimated that both are retransmitting the optical signal in synchronization, and then the retransmission control unit provided in the other optical data transmission device By re-sending the retransmission process at a retransmission time interval longer than the retransmission time interval according to, an opportunity to receive the optical signal retransmitted from the transmission unit of the other optical data transmission device at the reception unit of one optical data transmission device is ensured Will be able to do handshaking.

  The fourth feature configuration is an optical data transmission device in which the one optical data transmission device is installed in a mobile facility in addition to the first or second feature configuration described above. In the point.

  Usually, the number of fixed equipment is overwhelmingly larger than that of mobile equipment, so the retransmission control unit of the optical data transmission device installed in the mobile equipment is retransmitted by the retransmission control unit provided in the other optical data transmission device. Working efficiency is remarkably improved by changing the retransmission process so that the retransmission process is repeated at a longer retransmission time interval than the interval.

  An optical data transmission apparatus according to the present invention includes a transmission unit that modulates a transmission signal into a pulsed optical signal and outputs it, and a reception unit that receives the pulsed optical signal and demodulates it into a reception signal. An optical data transmission apparatus to be installed, and when a response from another optical data transmission apparatus to the optical signal output from the transmission section is not confirmed by the reception section, the optical transmission from the transmission section is performed at a predetermined retransmission time interval. A retransmission control unit that repeats a retransmission process for outputting a signal, wherein the retransmission control unit has a retransmission time longer than a retransmission time interval after the number of retransmissions reaches the predetermined number of times until the number of retransmissions reaches the predetermined number of times. It is set to repeat retransmission processing at intervals.

  As described above, according to the present invention, an optical communication apparatus that can reliably transmit and receive even when both optical data transmission apparatuses are set erroneously such that both are set to the transmission priority mode, and An optical data transmission apparatus can be provided.

Schematic perspective view of manufacturing equipment, wafer carrier equipment, transport cart in semiconductor device manufacturing equipment Circuit diagram of main parts of optical data transmission device (A) is explanatory drawing of the frame data comprised by the modulated bit information, (b) is explanatory drawing of the pulse period and pulse number of the modulated bit information. Time chart showing the sequence until half-duplex communication is established Time chart showing poor communication status where half-duplex communication cannot be established Time chart showing retransmission processing according to the present invention

  An embodiment of an optical communication apparatus according to the present invention and an optical data transmission apparatus incorporated in the optical communication apparatus will be described.

  As shown in FIG. 1, in a semiconductor device manufacturing facility, various manufacturing apparatuses 10 (10 a, 10 b, 10 c, 10 d) are arranged along a passage 13 as a fixing facility for sequentially performing predetermined processing on a semiconductor wafer. In order to automatically transfer the semiconductor wafer 21 between the manufacturing apparatuses 10, a transport carriage 30 serving as a moving facility for transferring and transferring the wafer carrier device 20 to and from the load port 11 provided in the manufacturing apparatus 10 is a traveling rail. 12 so that it can run along the road.

  The transport carriage 30 includes a chuck mechanism 36 for gripping the wafer carrier device 20 on a base 31 having a traveling mechanism 32 that self-travels along the traveling rail 12 installed in the upper space of the manufacturing apparatus 10. An elevating mechanism 33 that elevates and lowers the elevating body 35 along a predetermined elevating path is incorporated.

  The elevating mechanism 33 includes an elevating body 35, a plurality of belts 34 having one end fixed to a predetermined position on the upper surface of the elevating body 35, and a winding shaft having the other end fixed to the base 31. An elevating motor that is rotationally driven is provided, and the belt 34 is wound or fed out by driving of the elevating motor, so that the elevating body 35 is configured to be movable up and down.

  The chuck mechanism 36 includes a pair of claws 37 for gripping the gripped portion on the upper surface of the wafer carrier device 20, and the claws 37 are gripped by driving of a gripping solenoid or motor provided in the elevating body 34. The wafer carrier device 20 is configured to be held or released by being in a holding posture or an opening posture.

  Such a transport cart 30 includes, for example, a system communication unit that can communicate with a host computer via a communication interface incorporated in the travel rail 12, and travels to a predetermined manufacturing apparatus 10 based on an instruction from the host computer. The wafer carrier device 20 is exchanged with the manufacturing apparatus 10.

  Further, in order to exchange the wafer carrier device 20 between the transport cart 30 and each manufacturing apparatus 10, the optical data transmission device 1 is incorporated in both. The optical data transmission apparatus 1 operates based on the SEMI E84-0200A interface standard.

  The transport carriage 30 controls the traveling mechanism 32 to move to a predetermined manufacturing apparatus 10 based on a command from the host computer via the system communication unit, and communicates with the manufacturing apparatus 10 via the optical data transmission apparatus 1. A control device for controlling the lifting mechanism 33, the chuck mechanism 36, and the like based on the transmission / reception data is mounted.

  As shown in FIG. 2, the optical data transmission apparatus 1 incorporates microcomputers 1a and 1b that transmit and receive predetermined frame data via a light emitting element and a light receiving element.

  The microcomputer 1a on the conveyance carriage 30 side permits communication by the optical data transmission apparatus 1 and a plurality of input / output signal lines 301 and 302 for transmitting / receiving data to / from the control apparatus 300 on the conveyance carriage 30 side. A signal line 303 is connected.

  The microcomputer 1b on the side of the manufacturing apparatus 10 has a plurality of input / output signal lines 101 and 102 for transmitting / receiving data to / from the control apparatus 100 on the side of the manufacturing apparatus 10 and a communication permission for permitting communication by the optical data transmission apparatus 1. A signal line 103 is connected.

  The microcomputer 1a on the transport carriage 30 side and the microcomputer 1b on the manufacturing apparatus 10 side respectively receive light-emitting diodes 2a and 2b that emit light at wavelengths in the near-infrared region and signal light output from the light-emitting diodes 2a and 2b. Photodiodes 3a and 3b for receiving light are connected. That is, data is transmitted and received by the combination of the light emitting diode 2a and the photodiode 3b and the combination of the light emitting diode 2b and the photodiode 3a.

  The signal light detected by the photodiodes 3a and 3b is binarized via the comparators 4a and 4b, which are binarization processing units, shaped into pulse signals, and input to the interrupt signal ports of the microcomputers 1a and 1b. It is configured to be.

  Further, the base terminals of switching transistors are connected to the output ports of the microcomputers 1a and 1b, and the light emitting diodes 2a and 2b are driven by pulse signals output from the output ports.

  Each of the microcomputers 1a and 1b emits light by modulating a transmission signal of a predetermined number of bits (for example, 8 bits) input from the control devices 300 and 100 via the input signal lines 301 and 101 into frame data for transmission. Frame data is reproduced from the transmission unit 5 that outputs an optical signal through the diodes 2a and 2b and the optical signal received through the photodiodes 3a and 3b, demodulated into a reception signal having a predetermined number of bits, and an output signal A receiving unit 6 for outputting to the control devices 300 and 100 via the lines 302 and 102 is provided.

  As shown in FIG. 3A, the frame data modulated by the transmission unit 5 includes a start bit STA indicating the head of the frame, a plurality of data bits D, a parity bit P indicating the parity of the data bits D, It consists of stop bits STP indicating the end of the frame.

  As shown in FIG. 3B, each bit information represented by 0 or 1 is 75 μsec. Or 105 μsec. Are defined as a combination of two types of pulse periods and two types of pulses, 11 pulses or 6 pulses.

  The start bit STA has a pulse period of 75 μsec. The number of pulses is 11, and the stop bit STP has a pulse period of 105 μsec. The number of pulses is 11, and 0 of each data bit D constituting the transmission signal has a pulse period of 75 μsec. The number of pulses is 6, and 1 of the data bit D has a pulse period of 105 μsec. The number of pulses is 6, and the parity bit P has a pulse period of 75 μsec. Or 105 μsec. The number of pulses is set to 6.

  Furthermore, during the pulse output period SP constituting each bit, that is, 500 μsec. Null period NP is set. Hereinafter, a series of pulse signal sequences detected in the pulse output period SP is also referred to as a bit group.

  That is, each bit information is modulated into a pulse signal sequence combining a predetermined arbitrary period and the number of pulses, and frame data in which a null period of a predetermined width is set between bits is transmitted between the optical data transmission apparatuses 1 Sent and received.

  The receiving unit 6 measures the period and the number of pulses of the pulse signal constituting each bit group received by the photodiode, and the period and the number of pulses are numerical values shown in parentheses in a predetermined allowable range (FIG. 3B). ) Is executed for all the bit groups to reproduce the frame data, and the data bit D is extracted from the properly reproduced frame data to receive the received signal. The demodulation process to be taken out is executed.

  The period and number of pulses indicating the bit information and the combination thereof, the length of the null period, and the number of data bits included in the frame data can be arbitrarily set according to the system, and are limited to the above-described specific numerical values. It is not a thing. The transmission time of frame data of one frame depends on the number of bits of the transmission signal input from the control devices 300 and 100 via the input signal lines 301 and 101, but is usually several msec. To several tens of msec. Is set in the range.

  Returning to FIG. 2, each of the microcomputers 1 a and 1 b receives the optical signal from the optical data transmission device 1 on the other side at the reception unit, and then responds to the optical data transmission device 1 on the other side from the transmission unit. A reception standby mode for transmitting an optical signal and an optical signal transmitted from the transmitting unit on the own device side to the optical data transmitting device 1 on the other side before receiving the optical signal from the optical data transmitting device on the other side by the receiving unit. A mode setting unit 8 for setting the mode to any one of the transmission priority modes is provided.

  The mode setting unit 8 includes mode signal lines 104 and 304 for inputting the set mode to the microcomputers 1a and 1b, and switches 105 and 305 for switching the logic of the mode signal lines 104 and 304 to a high level or a low level. Yes.

  The input terminals of the mode signal lines 104 and 304 of the microcomputers 1a and 1b are pulled up to the power supply voltage. When the switches 105 and 305 are closed, a low level signal is input, and when the switches 105 and 305 are opened, they are high. A level signal is input.

  Usually, the mode is set depending on whether or not the mode signal lines 104 and 304 are grounded without providing the switches 105 and 305. The reception standby mode is set when the signal level of the mode signal lines 104 and 304 input to the microcomputers 1a and 1b is low, and the transmission priority mode is set when the signal level is high. Normally, the microcomputer 1a on the transport carriage 30 side is set to the transmission priority mode, and the microcomputer 1b on the manufacturing apparatus 10 side is set to the reception standby mode.

  Furthermore, each optical data transmission device 1 outputs an optical signal from the transmission unit 5 to the counterpart optical data transmission device 1 and receives the optical signal output in response to the counterpart optical data transmission device. 6 is provided with a retransmission control unit 7 that repeats a retransmission process for outputting an optical signal from the transmission unit at a predetermined retransmission time interval T1 until reception at 6. The retransmission control unit 7 is configured to operate only when the optical data transmission apparatus 1 is set to the transmission priority mode.

  The optical data transmission device 1 installed in the transport carriage 30 is prohibited from communicating by a control signal from the control device 300 via the communication permission signal line 303 while moving between the manufacturing devices 10, and the target manufacturing device 10. Communication is permitted by a control signal via the communication permission signal line 303.

  The optical data transmission apparatus 1 installed in the target manufacturing apparatus 10 is also permitted to communicate by a control signal via the communication permission signal line 103 when the transport carriage 30 reaches the own apparatus.

  The optical data transmission device 1 installed in the transport carriage 30 outputs an optical signal to the optical data transmission device 1 installed in the manufacturing device 10 and a response from the optical data transmission device 1 installed in the manufacturing device 10. Until the optical signal is received by the receiving unit 6, the optical signal is retransmitted at the retransmission time interval T1, and when the response optical signal from the optical data transmission device 1 installed in the manufacturing apparatus 10 is received by the receiving unit 6, After that, transmission / reception is started by the half-duplex communication method.

  When the optical axis of both optical data transmission apparatuses 1 coincides when the transport carriage 30 is stopped, the communication permission signal input to the optical data transmission apparatus 1 installed in the manufacturing apparatus 10 is delayed and the reception process is delayed. Even if it exists, since the optical signal is retransmitted from the optical data transmission apparatus 1 installed in the transport cart 30, the optical data transmission apparatus 1 installed in the manufacturing apparatus 10 is appropriately lighted when a communication permission signal is input thereafter. The signal can be received.

  The reason why the half-duplex communication method is employed is to avoid erroneous reception in which the optical signal output from the transmission unit 5 on the own device side is received by the reception unit 6 on the own device side as stray light. While the optical signal is output from the transmission unit 6 on the side, the reception unit 6 on the own device side is prohibited from receiving the optical signal.

  The retransmission time interval T1 is a value obtained by adding a predetermined margin to the average frame data transmission time or reception time. For example, the average frame data transmission time T is 30 msec. If the retransmission time interval T1 is 40 msec. Set to degree. This value is merely an example, and the retransmission time interval T1 is a value that is appropriately set according to the system.

  FIG. 4 shows a sequence until half-duplex communication is established. When the transport carriage 30 reaches the stop position at time t <b> 1 and a control signal is input via the communication permission signal line 103 to the optical data transmission apparatus 1 installed in the manufacturing apparatus 10, communication is permitted. The optical data transmission device 1 installed in 1 waits for reception of an optical signal of one frame output from the optical data transmission device 1 installed in the transport carriage 30.

  Thereafter, when both optical axes coincide and a control signal is input via the communication permission signal line 303 to the optical data transmission apparatus 1 installed on the transport carriage 30 at time t2, communication is permitted. The optical data transmission device 1 installed in 1 receives the optical signal and outputs a response signal to the optical data transmission device 1 installed in the transport carriage 30.

  When the optical data transmission device 1 installed in the transport carriage 30 receives the response signal, it is handshaked and half-duplex communication is established. When the communication permission signal to the optical data transmission device 1 installed in the manufacturing apparatus 10 is delayed, the optical signal of one frame is transmitted from the optical data transmission device 1 installed in the transport carriage 30 at the retransmission time interval T1. Is repeatedly output.

  However, as shown in FIG. 5, if the optical data transmission apparatus 1 installed in the manufacturing apparatus 10 is set erroneously such that the transmission priority mode is set, the light installed in the manufacturing apparatus 10 at time t1. An optical signal is output from the data transmission apparatus 1.

  Thereafter, when communication is permitted by inputting a control signal via the communication permission signal line 303 to the optical data transmission apparatus 1 installed in the transport carriage 30 at time t3, the optical data transmission apparatus installed in the transport carriage 30. 1 also outputs an optical signal.

  At this time, when the input timing of the control signal via the communication permission signal line 303 coincides with the retransmission timing from the optical data transmission apparatus 1 installed in the manufacturing apparatus 10, both retransmission control units operate almost simultaneously and are the same. The optical signal is output in synchronization with the retransmission time interval T1, and the communication failure state continues. FIG. 5 shows such a communication failure state.

  Therefore, as shown in FIG. 6, the retransmission control unit 7 provided in the optical data transmission apparatus 1 installed in the transport carriage 30 is installed in the manufacturing apparatus 10 until the number of retransmissions reaches a predetermined number, for example, 10 times. The retransmission control unit 7 provided in the optical data transmission apparatus 1 is set to repeat the retransmission process at a retransmission time interval T2 longer than the retransmission time interval T1, and then retransmit at the retransmission time interval T1.

  The number of retransmissions n at the retransmission time interval T2 is preferably set to a plurality of times so that a chance of handshaking can be surely obtained, and may be a value that can avoid burst-like external noise.

  If comprised in this way, the setting of the mode setting part 8 will generate | occur | produce an error temporarily, and both retransmission of the optical data transmission apparatus 1 installed in both the manufacturing apparatus 10 which is a fixed installation, and the conveyance trolley 30 which is a moving installation. Even when the optical signal is retransmitted from each transmission unit 5 by the control unit 7, the retransmission control unit 7 included in the optical data transmission device 1 of the transport carriage 30 is used by the optical data transmission device 1 of the manufacturing apparatus 10. Since the retransmission processing is repeated at a retransmission time interval T2 longer than the retransmission time interval T1 by the retransmission control unit 7 provided for the transmission control unit 7, the optical signal is retransmitted from the transmission unit 5 of the optical data transmission device 1 of the transport carriage 30. The opportunity to receive the optical signal retransmitted from the transmission unit 5 of the optical data transmission device 1 of the manufacturing apparatus 10 at the reception unit 6 of the optical data transmission device 1 of the transport carriage 30 can be ensured, and the handshaking can be performed reliably. Yo To become. In FIG. 6, half-duplex communication is established at time t4.

  For example, the retransmission time interval T1 is 40 msec. Is set to several msec. To dozens of msec. If the length is set to be long enough, an opportunity to receive the optical signal retransmitted from the transmission unit 5 of the optical data transmission device 1 of the manufacturing apparatus 10 at the reception unit 6 of the optical data transmission device 1 of the transport carriage 30 during that time can be secured. While the optical signal is received by the receiving unit 6, transmission of the optical signal from the transmitting unit 5 is prohibited.

  That is, the retransmission time interval T2 may be set to be longer than the retransmission time interval T1 by at least the time that the start bit STA of the frame data can be recognized.

  Generally, the number of manufacturing apparatuses 10 installed in a semiconductor manufacturing facility is 1000 or more, and the amount of work for correcting an erroneous setting of the mode setting unit 8 of the optical data transmission apparatus 1 of the manufacturing apparatus 10 to a correct setting becomes enormous. However, the amount of work is much smaller if the optical data transmission device 1 of the transport carriage 30 having a smaller number is modified.

  Specifically, the control program that functions as the retransmission control unit 7 of the microcomputer 1a of the optical data transmission device 1 of the transport carriage 30 may be replaced. You may memorize | store in ROM of the data transmission apparatus 1. FIG.

  In addition, a switch that switches between retransmitting at the retransmission time interval T1 and retransmitting at the retransmission time interval T2 is switched to the control program that functions as the retransmission control unit 7 of the microcomputer 1a of the optical data transmission device 1 of the transport carriage 30 in advance. It may be incorporated in the data transmission device 1 and may be configured to automatically switch the retransmission time interval by detecting which switch is operated by the microcomputer 1a.

Hereinafter, another embodiment of the present invention will be described.
In the above-described embodiment, the optical data transmission apparatus 1 installed in the manufacturing apparatus 10 until the retransmission control unit 7 provided in the optical data transmission apparatus 1 installed in the transport cart 30 reaches the predetermined number of retransmissions. In the example described above, when the retransmission process is set to be repeated at a retransmission time interval T2 longer than the retransmission time interval T1 by the retransmission control unit 7 provided for Without limiting the number of retransmissions, the retransmission control unit 7 provided in the optical data transmission device 1 installed in the transport carriage 30 is operated by the retransmission control unit 7 provided in the optical data transmission device 1 installed in the manufacturing apparatus 10. The retransmission process may be set to be repeated at a retransmission time interval T2 longer than the retransmission time interval T1.

  In other words, the retransmission time interval at which the optical signal is retransmitted by the retransmission control unit 7 of the optical data transmission apparatus 1 that transmits and receives each other may be set to a different value.

  Further, the retransmission control unit 7 provided in the optical data transmission device 1 installed in the transport carriage 30 performs retransmission equal to the retransmission time interval T1 by the retransmission control unit 7 provided in the optical data transmission device 1 installed in the manufacturing apparatus 10. If the response to the optical signal output from the transmission unit 5 is not confirmed by the reception unit 6 even if the retransmission processing is repeated a predetermined number of times at the time interval T1, it is estimated that both are retransmitting the optical signal in synchronization. The retransmission processing may be set to be repeated at a retransmission time interval T2 longer than the retransmission time interval T1 by the retransmission control unit 7 provided in the optical data transmission device 1 installed in the apparatus 10.

  In the above-described embodiment, the case where the retransmission time interval by the retransmission control unit 7 provided in the optical data transmission device 1 installed in the transport carriage 30 is set longer than the other has been described as a preferred example. Needless to say, the retransmission time interval by the retransmission control unit 7 provided in the optical data transmission apparatus 1 installed in the manufacturing apparatus 10 may be set longer than the other.

  Each of the above-described embodiments is merely an example of the present invention, and the scope of the present invention is not limited by the description. The specific configuration of each part may be changed as appropriate within the scope of the effects of the present invention. Needless to say, you can.

  INDUSTRIAL APPLICABILITY The present invention can be widely applied to an optical data transmission apparatus that is used in manufacturing equipment and the like and performs communication between fixed equipment and mobile equipment using pulsed light propagating in space.

1: Optical data transmission device 1a, 1b: Microcomputer incorporated in optical data transmission device 5: Transmission unit 6: Reception unit 7: Retransmission control unit 8: Mode setting unit 10: Manufacturing device 11: Load port 12: Travel rail 20: Wafer carrier device

Claims (5)

An optical data transmission device including a transmission unit that modulates a transmission signal into a pulsed optical signal and outputs the received signal, and a reception unit that receives the pulsed optical signal and demodulates the received signal into a reception signal, respectively. An optical communication device that is installed and performs half-duplex communication between a fixed facility and a mobile facility,
Each optical data transmission device includes a retransmission control unit that repeats a retransmission process for outputting an optical signal from the transmission unit at a predetermined retransmission time interval when a response to the optical signal output from the transmission unit is not confirmed by the reception unit. Prepared,
An optical communication device in which the retransmission control unit provided in one optical data transmission device is set to repeat retransmission processing at a retransmission time interval longer than the retransmission time interval by the retransmission control unit provided in the other optical data transmission device .   The retransmission control unit provided in one optical data transmission apparatus performs retransmission processing at a retransmission time interval longer than the retransmission time interval by the retransmission control unit provided in the other optical data transmission apparatus until the number of retransmissions reaches a predetermined number. The optical communication device according to claim 1, wherein the optical communication device is set so as to repeat.   The retransmission control unit provided in one optical data transmission apparatus outputs from the transmission unit even if the retransmission process is repeated a predetermined number of times at a retransmission time interval equal to the retransmission time interval by the retransmission control unit provided in the other optical data transmission apparatus. The retransmission processing is set to be repeated at a retransmission time interval longer than a retransmission time interval by a retransmission control unit provided in the other optical data transmission apparatus when a response to the received optical signal is not confirmed by the receiving unit. The optical communication device according to 1.   3. The optical communication apparatus according to claim 1, wherein the one optical data transmission apparatus is an optical data transmission apparatus installed in a mobile facility. An optical data transmission apparatus installed in a mobile facility, comprising: a transmission unit that modulates a transmission signal into a pulsed optical signal and outputs it; and a reception unit that receives the pulsed optical signal and demodulates it into a reception signal. And
A retransmission control unit that repeats a retransmission process of outputting an optical signal from the transmission unit at a predetermined retransmission time interval when a response from another optical data transmission apparatus to the optical signal output from the transmission unit is not confirmed by the reception unit With
The retransmission control unit is configured to repeat retransmission processing at a retransmission time interval longer than a retransmission time interval after the number of retransmissions reaches the predetermined number of times until the number of retransmissions reaches the predetermined number of times. Transmission equipment.

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