JP2679142B2 - Multiplex transmitter / receiver - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmitting / receiving apparatus such as a robot used in an automobile assembly process.

(Prior Art) Conventionally, in a control device for processing and assembly, for example, in an assembly process of a welding robot or the like, each processing station is controlled by a central control device, but each processing station has an electric component to be controlled. There are several dozen or more for each station, and its power supply system including the electrical parts to be controlled,
For example, the power supply systems of solenoid valves are connected by the same number of transmission lines for control transmission as the number thereof.

(Problems to be Solved by the Invention) However, in such a processing and assembly control device, the central control device and the solenoid valves of each processing station are wired using the same number of transmission lines as the number of solenoid valves. Since the connection is made, the wiring work is extremely complicated and the wiring connection becomes complicated. By the way, when a failure such as a short-circuit accident occurs in the electrical system including the solenoid valve, it is necessary to confirm which solenoid valve power supply system the location where the short-circuit accident occurred in and perform repair work. However, if the failure information is detected and returned to the control center in order to confirm the occurrence of a failure such as a short-circuit accident, the same number of transmission lines as the number of solenoid valves are required, and the wiring becomes more complicated. There is a problem.

(Object of the Invention) The present invention has been made in view of the above problems, and an object of the present invention is to reduce the occurrence of an abnormality in a power supply system including electrical components while reducing wiring. An object of the present invention is to provide a multiplex transmission / reception device capable of identifying a location and implementing measures such as repair.

(Means for Solving the Problems) A modulated control command pulse, which is provided on the transmission side and includes address information and on / off information of a plurality of electric components on the reception side, is transmitted as a serial pulse signal via a transmission path. A transmitting side transmitting section for transmitting to the receiving side, and demodulating the control command pulse transmitted through the transmission path provided in the receiving side, and based on the address information and on / off information, the address thereof. A demodulation circuit for driving an electric component corresponding to the information, and a power supply system including the electric component to be driven on the reception side are respectively provided for detecting whether the power supply system is normal or abnormal. The abnormality detection circuit, and the detection information output by the abnormality detection circuit, the detection information output during the period between the pulse corresponding to the address of the detection information of the control command pulse is transmitted. A receiving side transmitting section for transmitting to a transmitting side via a transmission line, and a transmission for switching to receivable only during a period between pulses of a control command pulse transmitted to the receiving side for receiving the detection information. And a side receiver.

(Operation) The transmission section on the transmission side transmits the modulated control command pulse containing the address information and on / off information of the electric component to the reception side via the transmission path as a serial pulse signal. Then, when the abnormality detection circuit outputs the detection information, the reception-side transmission unit blocks the period between the pulse corresponding to the address of the detection information among the control command pulses transmitted via the transmission path. Then, the detection information is transmitted via the transmission path, and the transmission side receiving unit receives the detection information by switching to the receivable period only between the pulses of the control command pulse. Information is sent and received at the same time. Moreover, since the detection information is transmitted during the period between the pulse corresponding to the address of the detection information of the control command pulse and the pulse, the address information of the power supply system is also transmitted.

That is, since the control command pulse is a serial pulse signal, even if the number of signal lines is one, the control command pulse and the detection information can be transmitted and received at the same time, and the detection information corresponds to the pulse corresponding to the address. By transmitting during the period between the pulse and the pulse, it is possible to simultaneously transmit the presence / absence of an abnormality in the power supply system and the address of the power supply system in real time.

(Embodiment) Hereinafter, a case where the multiplex transmission / reception device of the processing / assembly control device according to the present invention is used as a control device of a welding robot device will be described with reference to the drawings.

FIG. 2 schematically shows a wiring system of a processing and assembly control device used in a welding robot for welding a vehicle body. In the drawing, 1 is a central control device main body as a transmission side, and 2 is a transmission side. The repeater box 3 on the receiving side is a transmission line that connects the central control unit body 1 and the repeater box 2. The central control device body 1 has a function of transmitting a control command pulse, which will be described later, to the repeater box 2 via the transmission path 3.

As shown in FIG. 1, the central control device body 1 has a transmitting side transmitting section 4, a transmitting side receiving section 5, and a control device 6. The control device 6 outputs a command information for selecting an address of a demodulation circuit which will be described later, address information for designating an address of a solenoid valve as an electrical component which will be described later, and on / off information of the solenoid valve at the designated address. And a function for outputting command information including and.

The transmission side transmission unit 4 is based on the command information of the control device 6,
It has a function of outputting a control command pulse including address information and on / off information of the solenoid valve as a serial pulse signal to the relay box 2 via the transmission path 3. The transmission side transmission unit 4 is roughly composed of a transistor 7, a photocoupler 8 for turning on / off the transistor 7, and an inverter 9 connected to the control device 6. The transmitting side receiving section 5 has a function of receiving the detection information of the receiving side transmitting section provided on the receiving side, and the photo couplers 11 and 12 are provided.
And the inverters 13 and 14 are generally configured. In addition,
The configuration and function of the reception side transmission unit will be described later.

The photocoupler 8 is a light emitting diode 8a and a phototransistor.
8b. The anode of the light emitting diode 8A is connected to the 12-volt voltage applying line 8c through the resistor 8d, and the cathode of the light emitting diode 8a is connected to the output terminal of the inverter 9. The input terminal of the inverter 9 is connected to the control device 6.

The collector of the phototransistor 8b is a 24V voltage application line.
7a and the collector of the transistor 7. The base of the transistor 7 is connected to the emitter of the phototransistor 8b, the emitter of the transistor 7 is connected to the 24 volt voltage applying line 7a via the diode 7b, and the connection terminal connected to the signal line 3a of the transmission line 3. It is connected to 3a '. The transmission line 3 is a signal line
In addition to 3a, it has a 24V voltage application line 3b and a ground line 3c.
b'is a connection terminal of the voltage application line 3b, and 3c 'is a connection terminal of the voltage application line 3c.

The photocoupler 11 includes a light emitting diode 11a and a phototransistor 1.
1b, the photocoupler 12 has a light emitting diode 12a and a phototransistor 12b. The anode of the light emitting diode 11a is connected to the 12-volt voltage applying line 8a through the resistor 11c, and the cathode of the light emitting diode 11a is connected to the inverter 14a.
Output terminal. The input terminal of the inverter 14 is connected to the control device 6 via the inverter 13.

The collector of the phototransistor 11b is a light emitting diode 12a.
Is connected to the connection terminal 3a ′ via
The emitter of b is connected to the earth terminal 3c 'via the line 12d. The emitter of the phototransistor 12b is grounded, and the collector of the phototransistor 12b is connected to the control device 6 and also connected to the 12-volt voltage applying line 8a through the resistor 12c.

The command information of the control device 6 is composed of high-low phase-modulated time-division multiplexed signals, and the command information is input to the inverters 9 and 13. When the command information is H, the output of the inverter 9 and the output of the inverter 13 are both L. When the output of the inverter 9 is L, the light emitting diode 8a of the photocoupler 8 emits light and the phototransistor 8b
Is turned on, and the transistor 7 is turned on. On the other hand, when the output of the inverter 13 is L, the output of the inverter 14 is H, so the light emitting diode 11a of the photocoupler 11 does not emit light,
The phototransistor 11b is non-conductive.

As a result, a current flows from the power supply potential (24V) side toward the relay box 2 via the signal line 3a.

On the other hand, when the command information is L, the outputs of the inverters 9 and 13 are both H. When the output of the inverter 9 is H, the light emitting diode 8a of the photocoupler 8 does not emit light and the phototransistor 8b becomes non-conductive. Therefore, the transistor 7 is turned off, and the current flowing from the power supply potential (24V) side toward the relay box 2 via the signal line 3a is cut off.

Therefore, if the command information is configured so that the control command pulse S shown in FIG. 3 (a) is obtained, a high / low signal is generated as a control command pulse via the transmission line 3 in accordance with ON / OFF of the transistor 7. Will be transmitted to the repeater box 2.

At this time, the output of the inverter 14 is
Since the output of 13 is H, it becomes L and the light emitting diode 12a
Emits light, and the phototransistor 12b becomes conductive, whereby the light emitting diode 11a of the photocoupler 11 emits light, the phototransistor 11b becomes conductive, and it becomes possible to receive detection information from the receiving-side transmitting unit described later. The reception of the detection information from the receiving side transmitter will be described later.

The repeater box 2 has connection terminals 13a, 13b, 13c, an address selector 13, and eight demodulation circuits 14-21.
The address selector 13 determines which control command pulse S of the eight demodulation circuits has been transmitted through the signal line 3a, and makes the control command pulse S correspond to the control command pulse S. It has a function of transmitting to the demodulation circuit. The configuration of the control command pulse S will be described later.

Here, 32 solenoid valves with one demodulation circuit
25 (electrical parts) can be selectively driven. The demodulation circuit has one 5-bit counter to specify the address of the 32 solenoid valves 25 for each, and the 32 solenoid valves 25 are divided into 4 groups, and 8 solenoid valves are provided. It is organized as a group.
In the 5-bit counter, the upper 2 bits are used to specify the addresses of the four groups, and the lower 3 bits are used to specify which solenoid valve 25 of the group is driven. Hereinafter, the control command pulse S corresponding to the demodulation circuit 14 is transmitted to the repeater box 2
It will be described in detail as it was sent to.

The control command signal S is address information for designating the solenoid valve 25 to be driven during the section from the fall of the blanking signal BK to the rise of the next blanking signal BK shown in FIG. 3 (a). And a pulse train including on / off information for driving the solenoid valve 25. The section is equally divided into 32 subsections, and one pulse is included in each of the subsections. The width of the pulse included in the narrow section corresponds to ON information of the solenoid valve 25 to be driven, and the trailing edge of the pulse corresponds to the address of the solenoid to be driven.

Connection terminal 13a is a 12 volt regulator via line 13d
Connected to 26. A backflow prevention diode 27 is provided in the middle of the line 13d. This backflow prevention diode 27 includes a photocoupler 28 and a switching transistor 2
Together with 8 ', the receiving side transmitter 29 is configured. Photo coupler 2
Reference numeral 8 has a light emitting diode 28a and a phototransistor 28b. The anode of the backflow prevention diode 27 is connected to the emitter of the phototransistor 28b via the resistor 27a, and the cathode of the backflow prevention diode 27 is connected to the phototransistor 28b.
It is connected to the collector of b. The anode of the light emitting diode 28a is connected to the 12-volt voltage applying line 8a via the resistor 30, and the cathode thereof is connected to the collector of the switching transistor 28 '. The emitter of the switching transistor 28 'is grounded, the detection information is input to the base through the resistor 28'a, and when the detection information is H, the switching transistor 28' is turned on. When 28 'turns on, the light emitting diode 28a emits light and the phototransistor 28b
Becomes conductive and current can flow from the side of 24 V toward the transmission side through the transmission line 3. At this time, the transistor 7 of the transmitting side transmitting unit 4 is off.

The control command pulse S is directly input to the integrator 31, and is also input to the low pass filter 35 via the Zener diode 32, the resistor 33, and the inverter 34. The inverter 34 is connected to the inverter 35, and the inverter 35 is connected to the non-triggerable monostable multivibrator 36. The monostable multivibrator 36 has a function of generating the clock signal CK shown in FIG. 3C based on the fall of the control command pulse S.

The low-pass filter 35 is for removing the harmonic component contained in the control command pulse S. The low-pass filter 35 has a function of passing the blanking signal BK of the control command pulse S. BK is used as a reset signal R (see FIG. 3B) for the 5-bit counter 37 and 8-bit parallel latch circuit 38.

The clock signal CK is input to the 5-bit counter 37, the delay circuit 39, and the inverter 40. The count content of the 5-bit counter 37 is reset by the reset signal R, the clock signal CK is input, and the count content is updated as shown in FIG. 3 (d) and FIG. That is, when the first clock signal CK is input, the count content is updated from “00000” to “00001”,
When the second clock signal CK is input, the count content is updated from "00001" to "00010", and each time the clock signal 31 is input, the count content is changed. Depending on the count contents of this 5-bit counter 37,
Which of the 32 solenoid valves 25 is the command information is distinguished. The output side of the 5-bit counter 37 is connected to the four serial latch circuits 41. Note that, in FIG. 1, the other two serial latch circuits are omitted.

The upper 2 bits of the 5-bit counter 37 are used to select which of the four serial latch circuits 41, and 5 bits are used to select the address of the eight solenoid valves 25 connected to the serial latch circuit 41. The lower 3 bits of the counter 37 are used, and an address setter 42, a comparator 43, and a gate circuit 44 are used as a selection circuit of the serial latch circuit 41.

The upper 2 bits of the information of the 5-bit counter 37 and the address information of the address setter 42 are input to the comparator 43. When the information of the upper 2 bits and the address information match, the comparator 43 goes high and the comparator 43
The output of 43 is input to one terminal of the gate circuits 44 and 46. The gate circuit 44 is used for the latch timing of the serial latch circuit 41, and the other terminal of the gate circuit 44 is an inverter.
The output of 40 is differentiated by the differentiating circuit 47 and input. The serial latch circuit 41 shapes and stores the integrated output from the integrator circuit 31 at an address based on the information of the lower 3 bits of the 5-bit counter 37 by the latch timing signal from the gate circuit 44.

The integration circuit 31 executes integration during the integration interval shown in FIG. 3 (e), the delay circuit 39 and the inverter 48 have a function of setting the integration interval, and the integration circuit 31 has a clock. Starts integration after the signal CK
It is reset every predetermined time based on the output of the inverter 48 corresponding to the rise of CK. Therefore, the integration circuit 31
Will output an integrated output corresponding to the width of the pulse output during the narrow section of the blanking signal BK to the serial latch circuit 41. The integrated output becomes almost zero in the narrow section where the pulse width is narrow, and exceeds the predetermined level in the narrow section where the pulse width is wide, resulting in an integrated waveform as shown in FIG. It is latched as the data shown in FIG. 3 (g) in the four 8-bit serial latch circuits 41 selected in time series according to the bit information. The data shown in FIG. 3 (g) corresponds to the control command pulse S, the low portion means that the solenoid valve 25 corresponding to the address is not driven, and the high portion corresponds to the address. It means that the solenoid valve 25 corresponding to is driven.

The 8-bit serial latch circuit 41 outputs 8-bit information to the 8-bit parallel latch circuit 38 via the time constant circuit 50. The 8-bit parallel latch circuit 38 is reset based on the reset signal from the low pass filter 35, and latches the 8-bit information of the 8-bit serial latch circuit 41. The time constant circuit 50 is used, for example, to correct a signal reading error due to noise.

In the 8-bit parallel latch circuit 38, one solenoid driving power supply circuit 51 is connected to each signal output line of the 8-bit parallel latch circuit 38. The solenoid drive power supply circuit 51 includes transistors Tr1 and Tr2, and the transistors Tr1 and Tr2 are Darlington-connected. The collectors of the transistors Tr1 and Tr2 are both connected to the solenoid valve terminal SBL2. A power supply voltage of 24 V is applied to the solenoid valve 25 via the solenoid valve terminal SBL1, and the solenoid valve terminal SBL0
Is grounded. The solenoid valve terminal SBL1
Diode 52 between the solenoid valve terminal SBL2 and
Is interposed. By the way, the solenoid driving power supply circuit 51 corresponds to the power supply system of the solenoid valve 25.

The emitter of the transistor Tr2 is connected to the ground via the fuse 53. A resistor in parallel with its fuse 53
54 is connected, and the fuse 53 is designed to be blown when the solenoid valve 25 is short-circuited and an excessive current flows, and here, it is blown when a current of 2 A or more flows. The emitter of the transistor Tr2 is the fuse 53
When the fuse 53 is blown, the current rises slightly because the current flows through the resistor 54 when the fuse 53 is blown.

Here, the resistor 54 is configured such that a current of about 0.1 A flows to the solenoid valve 25 in relation to the solenoid valve 25, and even if the fuse 53 is blown due to a short circuit for some reason, The solenoid valve 25 having a rating of about 0.1 A is configured to operate normally immediately after an abnormality occurs.

The fuse 53, the resistor 54, and the transistor Tr2 form an abnormality detection circuit, and the emitter of the transistor Tr2 is connected to the base of the abnormality detection transistor Tr3 via the resistor 55. This abnormality detection transistor Tr3
Is one for each of the eight solenoids. The abnormality detection transistor Tr3 is turned off when there is no failure such as a short circuit in the power supply system of the solenoid valve 25, and when the collector is high, high is input to the other terminal of the gate circuit 46. Since the address selection information is input to one terminal of the gate circuit 46, the gate circuit 46 outputs a high level signal indicating normal when the control command pulse S is low when the solenoid valve 25 is operating normally. At this time, it outputs to the transistor 28 ', which turns on the transistor 28'.

When the transistor 28 'is turned on, the light emitting diode 28a emits light and the phototransistor 28b becomes conductive. At this time, since the light emitting diode 11a of the photocoupler 11 of the transmitting side transmitting section 5 emits light and the phototransistor 11b is in a conductive state, based on the 24 volt power supply voltage of the receiving side transmitting section 29,
A current flowing through the phototransistor 28b and flowing in the line 13d is generated, whereby a signal indicating normality is transmitted via the signal line 3a of the transmission line 3 as shown by an arrow, and the transmitting side receiving unit 5
Sent to

Based on the transmission of this normal signal, the photo coupler
The 12 light emitting diodes 12a emit light, and the phototransistor 12b
Becomes conductive. Therefore, the solenoid valve on the receiving side
There is 12 information corresponding to the signal which means 25 is normal.
Information that means that the electrical components to be driven by the control device 6 are normal is taken from the voltage application line 8a via the phototransistor 12b toward the control device 6, and the control command pulse S The detection information is transmitted from the receiving side 2 to the transmitting side 1 without any interval between the pulse trains.

When the solenoid valve 25 is abnormal, the failure detection transistor Tr3 remains off, so that the gate circuit 46 does not output a high-level signal.
Since the transistor 28 'remains off, the phototransistor 28b is non-conducting, and the current based on the 24 volt power supply voltage of the receiving transmitter 29 does not flow through the phototransistor 28b to the line 13d. Therefore, the abnormality of the solenoid valve 25 to be driven is detected.

If the normal signal is not sent within the low section of the control command pulse S corresponding to the abnormal address of the solenoid valve 25, the solenoid valve of which address
It is possible to determine whether 25 is abnormal.

As described above, the control command pulse S and the detection information are transmitted and received at the same time. Moreover, since the detection information is transmitted with a period between the pulse corresponding to the address of the detection information in the control command pulse S, the address information of the power supply system is also transmitted.

That is, since the control command pulse S is a serial pulse signal, even if the number of the signal lines 3a is one, the control command pulse S and the detection information can be transmitted and received at the same time, and the detection information can be sent to the address. By transmitting the corresponding pulse after the period between the pulses, the presence / absence of abnormality of the power system and the address of the power system can be simultaneously transmitted in real time. That is, it is possible to send the presence / absence of abnormality of the power supply system on the receiving side and the address information to the transmitting side in real time at the same time, while saving wiring.

(Effect of the Invention) Since the multiplex transmission / reception device of the processing / assembly control device according to the present invention is configured as described above, since the control command pulse is a serial pulse signal, the number of signal lines is reduced to one. Also, the control command pulse and the detection information can be transmitted and received at the same time, and further, the detection information is transmitted during the period between the pulses corresponding to the address, so that it is possible to determine whether there is an abnormality in the power supply system. The address of the power supply system can be simultaneously transmitted in real time. That is, there is an effect that the presence / absence of an abnormality in the power supply system on the receiving side and the address information can be simultaneously sent to the transmitting side in real time while saving wiring.

[Brief description of the drawings]

FIG. 1 is a specific circuit diagram of a multiplex transmission / reception device of a machining / assembly control device according to the present invention, and FIG. 2 is a schematic wiring system of the machining / assembly control device used in a welding robot for welding a vehicle body. FIG. 3 is a block diagram shown in FIG. 3, and FIG. 3 is a time chart diagram showing signals output from the main circuit of FIG.
FIG. 4 is an explanatory diagram showing the relationship between the contents of the 5-bit counter and the addresses. 1 ... Central control unit main body (transmission side) 2 ... Repeater box (reception side) 3 ... Transmission path 4 ... Transmission side transmission section 5 ... Transmission side reception section 14-21 ... Demodulation circuit 25 ... Solenoid valve (electrical parts) 51 …… Solenoid drive power supply circuit 29 …… Reception side transmitter

Claims (1)

(57) [Claims] 1. A modulated control command pulse, which is provided on the transmitting side and includes address information and on / off information of a plurality of electric components on the receiving side, is transmitted to the receiving side via a transmission line as a serial pulse signal. A transmitting side transmitting section for transmitting, and a receiving side, which demodulates the control command pulse transmitted via the transmission path and responds to the address information based on the address information and on / off information. A demodulation circuit for driving an electric component, and an abnormality detection circuit provided in each power supply system including the electric component to be driven on the reception side and detecting whether the power supply system is normal or abnormal The detection information output by the abnormality detection circuit is sent via the transmission path during a period between the pulses corresponding to the address of the detection information in the control command pulse being transmitted. A receiving side transmitting section for transmitting to the receiving side, and a transmitting side receiving section for receiving the detection information, which is switched to be receivable only during a period between pulses of a control command pulse being transmitted to the receiving side. Multiplexing transceivers.