JPH10143226A - System for connecting master station and slave stations - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly and wirelessly connect a master station (teacher equipment) with any prescribed slave station among plural slave stations (resistant welding controllers). SOLUTION: Concerning the master station and slave stations connecting system for wirelessly connecting teacher equipment (master station) 30 as a mobile object with any prescribed resistant welding controller (slave station) 20 among the plural resistant welding controllers 20, the teacher equipment 30 has a means for asking its ID number to the prescribed resistant welding controller 20 wirelessly and the prescribed resistant welding controller 20 wirelessly answers its own ID number to the teacher equipment 30 corresponding to that question. Then, since the teacher equipment 30 wirelessly sends its ID code to the prescribed resistant welding controller 20, the teacher equipment 30 is wirelessly connected with the resistant welding controller 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master / slave station connection system for wirelessly connecting a master station and a predetermined one of a plurality of slave stations.

[0002]

2. Description of the Related Art In a factory equipped with a plurality of resistance welding machines, the control is performed as follows. Each resistance welding machine is provided with a resistance welding control device (slave station). The resistance welding control device controls the clamping pressure between a pair of electrodes of the resistance welding machine, the current between the two electrodes, and the duration of current. Control contents are input to the plurality of resistance welding control devices (slave stations) from one portable teaching device (master station).

[0003]

A plurality of resistance welding control devices perform different control on each resistance welding machine. Therefore, one teaching device needs to transmit signals having different control contents to each resistance welding control device. For that purpose, the teaching device needs to specify each resistance welding control device and transmit appropriate control contents to the resistance welding control device. For the identification, there is a method using an ID number for each resistance welding control device.
However, if an ID number is set in advance for each resistance welding control device, which resistance welding control device
It is necessary to memorize or display whether or not it has a D number.

However, it is troublesome for an operator to store an ID number for each resistance welding control device.

Accordingly, an object of the present invention is to provide a system capable of smoothly and wirelessly connecting a master station and a predetermined slave station among a plurality of slave stations.

[0006]

According to a first aspect of the present invention, there is provided a wireless communication system between a parent station which is a mobile unit and a predetermined one of a plurality of child stations. A master / slave station connection system, wherein the master station wirelessly asks the predetermined slave station for the ID code of the slave station, and Means for wirelessly replying its own ID code to said master station, wherein said master station wirelessly sends said ID code of said slave station to said predetermined slave station, And the slave station are in a wireless connection state. Note that the ID code includes a four-digit number (ID number), an alphabet, a combination thereof, and the like.

According to the present invention, the worker asks the slave station that he / she wants to be in the connection state for the ID code, and based on the reply, makes the connection state. The need to store the ID code is avoided.

The invention according to claim 2 is the invention according to claim 1, wherein the slave station controls the resistance welding machine, and the master station controls the resistance welding control apparatus. A master / slave station connection system, which is a teaching device for inputting a password.

According to the present invention, the operation and effect of the invention according to claim 1 can be obtained between the resistance welding control device and the teaching device.

[0010] The invention according to claim 3 is the invention according to claim 1, wherein the predetermined slave station responds to the master station by selecting its own ID code from a random number. Features.

According to the present invention, when the slave station is asked for the ID code from the master station, the slave station selects and responds from the random number, thereby avoiding the necessity of setting the ID code in the slave station in advance. .

The invention according to claim 4 is the invention according to claim 3, wherein the ID code returned from the predetermined slave station to the master station is connected to the master station within a predetermined time. If the ID code is the same as the ID code of another slave station, the master station asks the slave station for the ID code again, and the slave station again selects its own ID code from the random number and replies. There is a feature.

When the control device determines its own ID code using a random number, the two control devices may accidentally determine the same ID code. In this case, interference occurs between the two control devices. Will be. However, according to the present invention, it is possible to prevent the same ID code as that of another slave station connected within a predetermined time from being determined, and to prevent the occurrence of such interference.

[0014] The invention according to claim 5 is the invention according to claim 1, wherein the signal transmission of the master station is performed before the master station is in a wireless connection state with the predetermined slave station. The directivity is narrow, and after the connection state is established, the directivity is widened.

In the present invention, since the directivity of the master station is narrow before the master station and the slave station are connected, interference such as inquiring of an ID code to slave stations other than a predetermined slave station occurs. In addition, since the directivity is widened after connection, the necessity of accurately pointing the master station to the slave station when transmitting from the master station to the slave station is reduced, and The operation of the station becomes simple.

The invention according to claim 6 is the invention according to claim 1, wherein the master station sends a cancel signal to the predetermined slave station, or the master station and the predetermined slave station communicate with each other. If no signal is exchanged for a predetermined time between the master station and the slave station, the connection state between the master station and the slave station is released.

According to the present invention, when the connection state between the master station and the slave station becomes unnecessary, the connection state is smoothly canceled.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> Next, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a large number of resistance welding machines 10 are provided in an automobile assembly plant or the like. Each resistance welding machine 10 has a pair of electrodes 11, a work is held between the pair of electrodes 11, and a welding current flows between the two electrodes 11 to perform welding of the work. Each resistance welding machine 10 is connected to a transformer 14 via a cable 12. The resistance welding control device 20 (slave station) is connected to the transformer 14 and is connected to a power supply. Resistance welding control device (hereinafter,
The control device 20 controls the clamping pressure between the two electrodes of the resistance welding machine 10, the current between the two electrodes, and the energizing time. As shown in FIG. 2, a transmission / reception adapter 22 is connected to the control device 20, and a monitoring device 24 is connected to the transmission / reception adapter 22.

Referring back to FIG. 1, one teaching device 30 (master station) is provided for many control devices 20. The teaching device 30 is also called a teaching box, and is portable. The teaching device 30 inputs (teaches) the control content of the control device 20 to the resistance welding machine 10 to the control device 20. As shown in FIG.
Has a keyboard 32, a display 34, and a transceiver 36. The keyboard 32 has a connection start key, a cancel key, and the like, in addition to the numeric keys. When the keyboard 32 is operated, signals based on light, radio waves, and sound (ultrasonic waves) are transmitted from the transceiver 36 to the transmission / reception adapter 22 (control device 20). In addition, the transmission / reception adapter 22 (the control device 20) transmits the
The signal is also transmitted to (teaching device 30). The display 34 displays the operation content when the keyboard 32 is operated, a signal transmitted from the control device 20, and the like.

Next, the operation of this system will be described with reference to the flowchart of FIG. The worker uses the teaching device 30
Control device 2 that wants to carry control contents while carrying (master station)
0 (slave station) and the teaching device 30 (transmitter / receiver 3
6) to the control device 20 (transmitter / receiver adapter 22)
The keyboard 32 of the teaching device 30 is operated to send a signal to the control device 20. That is, by pressing the connection start key of the teaching device 30 (Yes in Step S2 and Step S4), a connection command is transmitted from the teaching device 30 to the control device 20 (Step S6).

The control device 20 receives the signal (step S32), and if the signal is a connection command, determines its own slave station ID number (ID code) (steps S34 and S36). Is transmitted to the teaching device 30 (step S38). In this case, a random number is generated (step S34), and the own station ID number is determined based on the generated random number. An example is a 4-digit number. Then, the response command 1 is transmitted with the slave station ID number attached (step S38). The teaching device 30 includes the control device 20
Is received (step S8), and when it is confirmed that it is the response command 1 (Y in step S10)
es), and sends a confirmation command to the control device 20 with the slave station ID number attached (step S12). The control device 20 receives a signal from the teaching device 30 (step S40), which is a confirmation command, and its own slave station ID.
It is checked whether the number is a number (step S42). In the case of the own slave station ID number (Yes in step S42),
The response command 2 is transmitted with the slave station ID number attached (step S44). The teaching device 30 receives the signal from the control device 20 (step S14), and if it is the response command 2 and has the same slave station ID number as before, the connection state between the teaching device 30 and the control device 20 is changed. Established (steps S18, S46), teaching device 30 and control device 2
0 (the monitor device 24) is displayed to that effect (steps S20, S48). In this way, the worker can connect the predetermined control device 20 of the many control devices 20 and the teaching device 30 to a connected state. Then, in this state, predetermined control contents and the like can be input from the teaching device 30 to the control device 20.

In the above description, the control device 20 determines its own slave station ID number by using a random number. However, the present invention is not limited to this, and the originally determined slave station ID number may be used.

Next, the release of the connection state will be described. As shown in the flowchart of FIG. 4, the operator presses the cancel key of the teaching device 30 (step S200,
In step S202, a cancel command is transmitted with a slave station ID number whose connection is to be canceled (step S204). Control device 20 receives the signal, and if the cancel command is its own slave station ID number (Yes in step S222), transmits a cancel response command (step S224). The teaching device 30 receives the cancel response command (Yes in Steps S206 and S208), and cancels the connection state between the teaching device 30 and the control device 20 (Steps S210 and S226).

If there is no communication between the teaching device 30 and the control device 20 due to, for example, no operation being performed on the teaching device 30 for a predetermined time or more, the control device 2
The connection state with 0 may be canceled.

<Second Embodiment> Next, a second embodiment of the present invention will be described focusing on differences from the first embodiment. This embodiment differs from the first embodiment in that the directivity of transmission from the teaching device 30 changes. That is, as shown in the flowchart of FIG.
After pressing the 0 connection start key (Yes in step S2 and step S4), the directivity for transmitting radio waves and the like from the teaching device 30 to the control device 20 is narrow. Then, after the processes of steps S6 to S16 and steps S34 to S44 are performed in steps S52 and S70, respectively, and the connection state is established (steps S18 and S4).
6) The directivity of the teaching device 30 is widened (Step S)
54). In addition, narrowing or widening the directivity is performed by changing the spread of the propagation direction of radio waves or the like, or by changing the intensity of radio waves or the like.

Thereafter, normal communication processing is performed (steps S56 and S72), and steps S58 and S60 are performed.
Then, in steps S74 and S76, the connection state is released as in the flowchart of FIG. 4 of the first embodiment. In this embodiment, as described above, the directivity is narrowed until the connection state is established, and the directivity is widened after the establishment. Therefore, the directivity is narrow and the interference is reduced until the connection state is established.
It is possible to more reliably establish a connection state with the control device 20 to which control content is to be input. Further, once the connection state is established, the directivity is widened, so that the teaching device 30
Need to be accurately directed to the control device 20, and it becomes easier to transmit a signal from the teaching device 30 to the control device 20.

<Third Embodiment> Next, a third embodiment of the present invention will be described focusing on differences from the first embodiment. In the first embodiment, the control device 20 determines its own slave station ID number using a random number. But then,
It cannot be said that there is no case where the ID number is the same as the ID number of the other control device 20, and in that case, interference occurs. The present embodiment improves that point.

As shown in the flowchart of FIG.
As in the embodiment, steps S2 to S1 are performed by the teaching device 30.
0, and the control device 20 executes steps S30 to S3.
8 is performed. Whether the slave station ID number transmitted from the control device 20 is the slave station ID number of the control device 20 to which the teaching device 30 is currently connected (that is, immediately before) (step S100), It is determined whether or not it is the slave station ID number of the control device 20 (step S
102). If it corresponds to either, step S6
Return to That is, the confirmation command is not sent to the control device 20 without moving to step S12. For this reason,
Since the control device 20 does not receive the confirmation command within the predetermined time (No in step S110 or S42),
It returns to step S30. Then, the system waits for a connection command from the teaching device 30 again. On the other hand, step S1
If both No. 00 and S102 are No, step S
The process proceeds to 12, and the same processing as in the first embodiment is performed.
That is, the processing of steps S12 to S20 is performed by the teaching device 30, and the processing of steps S42 to S48 is performed by the control device 20. In this way, the same ID number as that of the control device 20 connected immediately before or within the predetermined time is prevented from being used.

In the teaching device 30, step S10
In step 4, the slave station ID number of the currently connected control device 20 is stored, and in step S106, the storage of the slave station ID number after the connection state has been canceled and a predetermined time has elapsed is deleted. In this way, the ID numbers of the currently connected control device 20 and the control device 20 connected within a predetermined time are stored, whereby the above-described steps S100 and S1 are performed.
02 is performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an apparatus according to an embodiment (first embodiment) of the present invention.

FIG. 2 is a block diagram schematically showing the apparatus of FIG.

FIG. 3 is a flowchart showing processing contents (processing up to connection) according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing processing contents (cancellation processing) of the first embodiment of the present invention.

FIG. 5 is a flowchart showing processing contents according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing processing contents according to a third embodiment of the present invention.

[Explanation of symbols]

 20 Resistance welding control device (slave station) 30 Teaching device (master station)

Claims (6)

[Claims] 1. A master / slave station connection system for wirelessly connecting a master station as a mobile unit and a predetermined slave station among a plurality of slave stations, wherein the master station is configured to receive the predetermined slave station. Means for wirelessly asking the slave station for the ID code of the slave station, and correspondingly, the predetermined slave station has means for wirelessly replying its own ID code to the master station, The master station transmits the ID of the slave station to the predetermined slave station.
A master / slave station connection system, wherein a wireless connection is established between the master station and the slave station by transmitting the code wirelessly. 2. The master / slave station connection system according to claim 1, wherein the slave station is a resistance welding control device that controls a resistance welding machine, and the master station is controlled by the resistance welding control device. A master / slave station connection system, which is a teaching device for inputting contents. 3. The master / slave station connection system according to claim 1, wherein the predetermined slave station responds to the master station by selecting its own ID code from a random number. A master / slave connection system characterized by the following. 4. The master / slave station connection system according to claim 3, wherein the ID code returned from the predetermined slave station to the master station is connected to the master station within a predetermined time. If the ID code is the same as the ID code of another slave station, the master station asks the slave station for the ID code again, and the slave station again selects its own ID code from the random number and responds. A master / slave station connection system, characterized in that: 5. The master / slave station connection system according to claim 1, wherein before the master station is in a wireless connection state to the predetermined slave station, a signal of the master station is transmitted. Is a master / slave connection system, wherein the directivity is narrow and the directivity is widened after being connected. 6. The master / slave station connection system according to claim 1, wherein the master station sends a cancel signal to the predetermined slave station, or the master station and the predetermined slave station. And a connection state between the master station and the slave station is released when no signal is exchanged for a predetermined time between the master station and the slave station.