JPH08114463A - Amplifier separating type sensor, amplifier separating type sensor system and threshold value setting method thereof - Google Patents

Abstract

PURPOSE: To make it possible to transfer the threshold value, which is set with one amplifier separating type sensor, to another sensor by providing a transmitting/receiving circuit and the means of discrimination, threshold value setting and the transmission and reception of the threshold value. CONSTITUTION: When a threshold value is set with a threshold value setting means 47c, an amplifier separating type sensor transfers the threshold-value data to another sensor as required. In this case, the sensor of the address of a copy or the origin of the copy is specified beforehand, and the data are transmitted with a threshold transmitting means 47d. In the amplifier separating type sensor, to which the threshold value is transmitted, the threshold value is received with a threshold-value receiving means 47e and set as the threshold value of a discriminating means 47b. When the same threshold value is enough even though there are many sensors, it is not necessary to set the threshold value for each sensor, and the setting proceduce of the threshold value can be simplified to the great extent. Even if the sensor part and the amplifier part the separated and set in the state wherein correspondence is ambiguous, the sensitivity setting of the amplifier separating type sensor is sufficient. Therefore, the adjusting work can be readily processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplifier separation type sensor constituted by separating a sensor head and a signal processing unit in a photoelectric sensor, a proximity sensor, etc., a sensor system including a plurality of amplifier separation type sensors and threshold setting thereof. It is about the method.

[0002]

2. Description of the Related Art Conventional detection sensors such as photoelectric sensors and proximity sensors are provided with a sensitivity adjusting resistor for setting sensitivity, and the resistance value is appropriately set. The proximity sensor and the photoelectric sensor are provided with a sensor head 201 provided with an oscillation coil and a resonance circuit as shown in FIG.
And a signal processing unit (hereinafter, referred to as an amplifier unit) 202 that detects an object based on other oscillation circuits and changes in the output thereof.
There are some that are provided separately. Also in the photoelectric switch, a so-called amplifier separation type sensor in which the light emitting / receiving unit and the other signal processing unit are separated is used. In such an amplifier separated type sensor, the amplifier units 202a to 202a-2
02d has a variable resistor for sensitivity setting, and this is performed by appropriately setting this resistance value. Since the sensor head can be downsized in the amplifier-separated type, as shown in FIG.
201d can be attached. You can also change the type of head that can be connected to the amplifier,
It is configured so that it can be selected according to the usage state. In this case, if one of the sensor head and the amplifier unit fails, it can be dealt with by exchanging either one, so that the time and cost required for maintenance can be reduced.

[0003]

However, such a conventional amplifier-separated sensor has the following problems. Since the sensitivity is adjusted by the variable resistor, the setting varies from worker to worker. Further, there is a drawback that adjustment requires experience and is troublesome. Even when it is used for the purpose of simply passing and detecting a detection object, it is necessary to set the sensitivity for each device. Therefore, even when it is sufficient to set the sensitivities of a large number of sensors with the same sensitivity as in the case of detecting the tightened state of the screws in FIG. 21B, it is necessary to adjust each sensor. Therefore, there is a drawback that the adjustment work is troublesome. The head of the amplifier-separated sensor is mounted in a narrow space, and the amplifier unit is often arranged at a place distant from the head or mounted in a control panel. In this case, in order to adjust the sensitivity, it is necessary to adjust the position of the near object by the sensor head and adjust the variable resistance in the amplifier section. Therefore, there is a drawback that a plurality of manpower is required, or one person has to go back and forth between the sensor head and the amplifier section to make an adjustment, which is troublesome.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to make it possible to appropriately set the set value set in one sensor to another sensor.

[0005]

According to a first aspect of the present invention, there is provided an amplifier separation type sensor in which a sensor head including a detection element and a signal processing section connected to the sensor head are separated. A transmitter circuit for driving the sensor head, a receiver circuit for receiving a signal from the sensor head, a judging means for judging the presence or absence of an object by comparing the input from the receiver circuit with a threshold value, the input from the receiver circuit and the teaching input. Threshold value setting means for setting the threshold value of the presence or absence of the object, threshold value transmitting means for transmitting the threshold value set by the threshold value setting means to another amplifier separation type sensor, and threshold value data transmitted from another amplifier separation type sensor Threshold value receiving means for receiving and setting as a threshold value of the determining means.

According to a second aspect of the present invention, there is provided a sensor unit having a slot to which a plurality of sensor modules are detachably attached, an interface circuit section with each sensor module, and data transfer means, and a sensor attached to the sensor unit. A sensor system comprising a module, wherein a sensor head including a detection element and a signal processing unit connected to the sensor head are separated from each other, and a transmission circuit for driving the sensor head and a sensor head are provided. A receiving circuit for receiving the signal, a discriminating means for discriminating the presence or absence of an object by comparing the input from the receiving circuit with a threshold, and a threshold for setting the threshold for the presence or absence of the object based on the input from the receiving circuit and the teaching input. The setting means and the threshold set by the threshold setting means are transmitted to another sensor module. A threshold transmission unit, receives the threshold data transmitted from another sensor module, and is characterized in that it has a, a threshold receiving unit configured to set as the threshold value determining means.

In the invention of claim 3 of the present application, the sensor system includes a remote console connected to the sensor unit of claim 2 via a cable, and the remote console is mounted in a slot of the sensor unit. A first selection switch for selecting a sensor module, a mode changeover switch for selecting a sensitivity setting mode and an operation mode, a teaching switch for inputting timing at the time of threshold setting, and a first for specifying a sensor module to which a threshold is to be transmitted. And two selection switches.

In the invention of claim 4 of the present application, the sensor head has a detection coil, and the transmission circuit of the signal processing unit is an oscillation circuit connected to the detection coil and a sensitivity adjustment circuit for changing the oscillation intensity thereof. The reception circuit of the signal processing unit is a detection circuit that detects the output of the oscillation circuit.

According to a fifth aspect of the present invention, the sensor head has a light projecting element and a light receiving element, and the transmission circuit of the signal processing section is a light projecting drive section for driving the light projecting element of the sensor head. The receiving circuit of the signal processing unit is a light receiving unit connected to the light receiving element of the sensor head.

According to a sixth aspect of the present invention, there is provided a method of transmitting a threshold value in the amplifier-separated sensor system according to the second aspect, wherein the copy destination sensor module is selected based on the threshold value of the sensor module that has already been set. Then, the set threshold value is transferred to the selected module, and the threshold value sent from another sensor module is written in the determination means of the sensor module.

The invention of claim 7 of the present application is the method of transferring a threshold value in the amplifier-separated sensor system according to claim 2, wherein a sensor module for which a threshold value has already been set is selected and selected. The threshold value of the selected sensor module is transferred to the designated sensor module, and the threshold value sent from the selected sensor module is written in the discriminating means of the sensor module.

[0012]

According to the inventions of claims 1 to 3 having the above characteristics, when the threshold value is set in the amplifier separation type sensor by the threshold value setting means, the threshold value data is transferred to another sensor as needed. . In this case, the sensor of the copy destination or the copy source is designated in advance, and the sensor is transmitted by the threshold transmitting means. In the amplifier separation type sensor to which this threshold value is transmitted, this threshold value is received by the threshold value receiving means and set as the threshold value of the discriminating means.

According to the invention of claim 4, the sensor head has an oscillation circuit and a sensitivity adjustment circuit together with the detection coil, and oscillates at a constant amplitude when an object does not approach the detection coil. Since the oscillation state changes when the object approaches, the detection circuit detects the decrease in the amplitude of the oscillation output to determine the presence or absence of the object.

Further, in the invention of claim 5 of the present application, a light emitting / receiving element is provided in the sensor head, and the light emitting element driving section of the signal processing section drives the light projecting element to change it after the receiving state by the approach of an object. The presence or absence of an object is determined.

[0015]

2 is an external view showing the structure of a sensor system according to an embodiment of the present invention. As shown in the figure, the sensor system includes a power supply unit 1A and a CPU unit 1B. Then, the sensor unit 11 is detachably attached to this sensor system. The sensor unit 11 is connected to the CPU unit 1B via the I / O bus and transmits information to and from the CPU unit 1B.

As shown in the perspective view of FIG. 3, the sensor unit 11 has slots 12-0 to 12-3 for inserting four sensor modules. Each slot 12-0 ~
Grooves 12-3 are formed in the left and right along the longitudinal direction, and a connector (not shown) for connecting to the sensor module 40 is provided in the innermost portion of each slot. A connector 13 for connecting a remote console, which will be described later, is provided below these slots. Further, elastic pieces 14 having claws for connecting to the CPU unit 1B are provided above and below.

Next, the structure of the sensor system 11 according to this embodiment will be described with reference to the block diagram of FIG.
First, in FIG. 4, a power supply unit 1A is for converting a commercial AC into a DC voltage, and power is supplied to the CPU unit 1B, the sensor unit 11, an I / O unit (not shown), and the like. The CPU (MPU) 21 including the operation program is provided in the CPU unit 1B, and the I / O bus 23, which is an information transmission path with the sensor unit 11 and the like, is connected via the communication LSI 22. Also CPU2
An RS232C interface 24 (I / F) and a console interface 25 are connected to the CPU 1, and various devices and consoles with an RS232C (not shown) can be connected to the CPU unit 1B. Furthermore, this C
In the PU unit 1B, the LS for communication is connected to the I / O bus 23.
I26 is connected, and further input devices such as various sensors are connected via the input interface 27.

When the sensor unit 11 is connected to the CPU unit 1B via the connector 14,
A communication LSI 31 is connected to the sensor unit 11 shown in FIG. 5 via an I / O bus 21. I / O bus 21
A DC / DC converter 32 is connected to the power source end of the inside to supply a necessary voltage to each part in the sensor unit 11.
The communication LSI 31 includes modules 0 to 3
The interfaces 33 of the four modules up to are connected, and the interface 34 for the console is also connected. Further, an LED 35 for displaying the operating state of the module connected to each slot of the sensor unit is connected. The sensor modules 40 inserted into the slots 12-0 to 12-3 are connected to these interfaces 33 as described above. Sensor module 40
A sensor head 41 is provided at the tip of each. In addition, the console interface 34 has a remote console 6
0 is connected.

Next, the module connected to the sensor unit 11 will be described. The sensor module 40 is shown in FIG.
As shown in the perspective view, a sensor for detecting an object, for example, a proximity sensor or a photoelectric sensor is configured together with the sensor head 41. FIG. 6A is a perspective view of the sensor module 40, and FIG. 6B is a front view thereof. As shown in the figure, the sensor module 40 has linear protrusions 42a and 42b in the longitudinal direction which are inserted into the slots of the sensor unit on the side wall, and a terminal fitting 43 for connecting the sensor head 41 is provided in front of it. Is provided. A panel surface 44 located on the front surface of the sensor unit when the sensor module is mounted on the sensor unit is provided on the side thereof.

FIG. 1 shows a sensor module 4 for a proximity sensor.
It is a block diagram which shows the general structure of 0. The sensor module 40 is provided in the arbitrary slot 12 of the sensor unit 11.
By being inserted into -0 to 12-N, it is connected to the module N interface 33 (N = 0 to 3). The sensor module 40 has a D connected to this interface.
It has a C / DC converter 45 and an input / output port 46.
An arithmetic and control unit (hereinafter referred to as CPU) 47 for controlling the operating state of the sensor module 40 is provided.

The sensor head 41 connected to the sensor module 40 for the proximity sensor includes an LC parallel resonance circuit, and an oscillation circuit 48 is formed together with this resonance circuit. The oscillation circuit 48 is provided with a sensitivity adjustment circuit 49 for adjusting its sensitivity. The sensitivity adjustment circuit 49 is an adjustment circuit for adjusting the oscillation sensitivity by changing the sensitivity adjustment resistance of the oscillation circuit 48 based on a switch signal from the outside. The output of the oscillation circuit 48 is input to the detection circuit 50 and converted into a DC level signal corresponding to the oscillation level. When the sensor module 40 is a proximity sensor, the oscillation circuit 48 and the sensitivity adjustment circuit 49 constitute a transmission circuit that drives the sensor head 41 together with a detection coil that is a detection element in the sensor head 41, and the detection circuit 50.
Constitutes a receiving circuit for receiving a signal from the sensor head 41.

The output of the detection circuit 50 is input to the A / D converter 47a in the CPU 47. The CPU 47 is also connected to a setting unit 51 for defining the threshold value and operating state of this sensor module. As shown in FIG. 6, the setting section 51 includes a teaching switch 52 and a mode changeover switch 5.
3. It has a copy switch 54 and a copy destination switch 55. The threshold setting means 47c is the mode switch 5
3 and teaching switch 52, teaching without a work, teaching without and with a work, and positioning teaching are performed respectively, as will be described later, and a sensitivity setting value is set by a switch signal to the sensitivity adjusting circuit 4
It is set to 9. The CPU 47 is the A / D conversion unit 4
Based on the output obtained from 7a, a discriminating means 47b for discriminating the presence or absence of an object with a predetermined threshold, a threshold setting means 47c for setting the threshold, and a threshold transmitting means 47d for transferring the set threshold to another sensor module. And a function of a threshold receiving unit 47e that receives the threshold transmitted from another sensor module. The mode changeover switch 53 sets the proximity sensor mode to the operation mode “RUN”, the set mode “SET” for sensitivity setting, and the copy mode “C”.
It is switched to "OPY". Then, the threshold value is held in the memory 56. The discrimination output obtained from the CPU 47 is input to the display element 57 for operation display and the display element 58 for stable operation display. The discrimination output is input to the module interface 33 of the sensor unit 11 via the input / output port 46.

FIG. 7 is a circuit diagram showing the configuration of the parallel resonance circuit, the oscillation circuit 48, and the sensitivity adjustment circuit 49 of the sensor head 41 of this embodiment. In this figure, the same parts as those of the conventional example described above are designated by the same reference numerals, and detailed description thereof is omitted. In this embodiment, an oscillating circuit 48 having diodes D1 and D2 and transistors Q1 to Q4 is connected to the parallel resonance circuit. As the sensitivity adjusting resistor Re of the oscillator circuit 48, a resistor group including resistors _RA , _RB1 , _RB2 , _RB3 ... Is connected in parallel as shown in the figure. Resistance R _B1 , R _B2 , R
_B3 ... Are connected to switches SW1, SW2 ... As switch circuits for switching them. These switches are opened and closed based on a switch signal from the CPU 47, and a parallel combined resistance is used instead of the emitter resistance of the transistor Q2, that is, the sensitivity adjustment resistance Re.
Therefore, the sensitivity of the oscillation circuit can be adjusted by the control of the CPU 47. Here, the number of switches is set to 11 from SW1 to SW11, and the resistors respectively connected in series to them are also set to R _{B1 to} R _B11 . It is assumed that these resistors R _{B (i)} have resistance values such that R _Bi = R ₀ · 2 ⁱ (i = 1 to 11). In this way, the combined resistance value Re can be set in 2048 steps by turning on and off the 11-bit switches SW1 to SW11.

Next, the remote console 60 connected to the sensor unit 11 will be described with reference to FIG. In the remote console 60, when the distance between the sensor unit 11 and the sensor head 41 of the present embodiment becomes large, and sensitivity adjustment becomes difficult at a position where an object is detected, such as in the vicinity of the conveyance line where the sensor head 41 is installed. Used. The remote console 60 sets the sensitivity of the sensor module and the sensor head installed in each slot,
When the sensitivity is copied, it is connected to the connector 13 of the sensor unit 11. As shown in the figure, the remote console 60 has a module selection switch 61 for selecting a slot into which a sensor module whose sensitivity is to be adjusted is inserted,
"SET" mode, "RUN" mode and "COPY"
It has a mode switch 62 for switching modes, a stable operation indicator lamp 63 for displaying stable operation, an operation indicator lamp 64 for displaying operation indicator, a two-color teaching indicator lamp 65 for displaying a teaching state, and a teaching switch 66. There is. Further, the remote console 60 has a copy destination switch 67 and a copy switch 68 for designating a copy destination.
Is provided. The copy-destination switch 67 transfers data to all except the module number key for selecting the sensor modules 0 to 3 and the sensor module for which the sensitivity is set.
A "LL" key and a reset key are provided. The module selection switch 61 is a first selection switch for selecting a sensor module to be adjusted, and the copy destination switch 67 is a second selection switch for selecting a module to which a threshold is to be transmitted. The remote console 60 sets the sensitivity of the sensor connected to each sensor module based on the display of these switches and indicators, and is used for copying the threshold value to other sensor modules.

FIG. 9A is a graph showing the change in the conductance g of the coil of the parallel resonance circuit with respect to the set distance L to the detection object (workpiece) 3, and FIG. 9B is the value of the sensitivity adjustment resistance (composite resistance) Re. 6 is a graph showing a change in operating distance L until the oscillation is stopped. Further, FIG. 10 is a flowchart showing the entire operation in the case of sensitivity adjustment (teaching). At the time of teaching, first in step 71, set the mode selector switch 53 to "RUN".
To "SET" mode. At this time, as shown in FIG. 9C, it is assumed that the detection object is not approached in front of the sensor head 41. Then, the teaching switch 52 is first depressed. By doing so, the routine proceeds to the routine 73, and the workpiece-less teaching process is executed.

FIG. 11 is a flow chart showing the operation of this teaching process without a work. Sensitivity adjustment circuit 49
Is the resistance value of the sensitivity adjusting resistor corresponding to the pointer n. This pointer n is, for example, 11 bits, that is, a value of 0 to 2047, and all the switches S in Re (0).
W1 to SW11 are turned on to set Re to the minimum state, and R
At e (2047), all the switches SW1 to SW11 are off, that is, Re is in the maximum state, and during this period, it changes corresponding to n. First, in step 81, the pointer n is set to 0, and the sensitivity adjustment resistance Re is set to Re (0), that is, the minimum value. At this time, since Re is the minimum value, the oscillation circuit 48 oscillates at a steady value as shown in FIG.
The state is sufficiently higher than the threshold Vth set to 7b. Now, proceeding to step 82, the pointer n is incremented and Re (n) is set in the sensitivity adjustment circuit 49 via the output port. Then, the routine proceeds to step 83, where it is checked whether or not the oscillation amplitude is reduced and is below the threshold value. If it is not less than the threshold value, the process returns to step 82, the pointer n is further incremented, and the same processing is repeated.
In this way, the value of the pointer n is successively increased and the value of the sensitivity adjustment resistor Re (n) is increased.

In this way, the amplitude sharply decreases at a specific value of the sensitivity adjusting resistor, and oscillation stops. Then, the process proceeds from step 83 to step 84, and the sensitivity adjustment resistance value Re (n) at this time is set to Re (N). The oscillation circuit 48 suddenly stops oscillating at a constant value of Re. This is Figure 9
In (b), the curve indicating the oscillation stop is shown to be horizontal. Therefore, the distance L1 at this time is the maximum detection distance of the sensor head of the parallel resonance circuit 1. Therefore, in order to detect the object stably, it is necessary to set a distance shorter than this. At this time, the distance L1 in FIG.
Let g ₁ be the conductance of the coil corresponding to. Then, the routine proceeds to step 85, where the sensitivity adjustment resistance Re (A) in the no teaching is determined by the relationship with Re (N).
That is, Re (A) is the resistance value of Re (N) with a predetermined coefficient α,
For example, it may be a value multiplied by 0.7 to 0.8 (where 0 <α
<1). Also, the value obtained by subtracting the constant value Rx from Re (N) is R
It may be set as e (A).

Now, when the teaching without a work of the routine 73 is completed, the routine proceeds to step 74 of FIG. 10 and it is checked whether or not the mode changeover switch 53 is in the "RUN" state or the "COPY" state. If it is in the "RUN" state, the sensitivity setting is completed only by the teaching without a work, and therefore the normal operation mode is entered. When in the copy mode, the data transfer process is executed as shown in FIG.

Next, the processing in the copy mode is shown in FIG.
This will be described with reference to the flowchart in FIG. When the copy process is started, first, at step 91, it is checked whether the module number key or the "ALL" key of the copy destination switch 55 is pressed. If any key is pressed, the process proceeds to step 92 and the memory of the copy destination sensor module is set to the writing state. Next, in steps 93 and 94, the reset key or copy switch 5
Check if 4 was pressed. If the reset key is pressed, the write state of the copy destination memory is canceled in step 95. Then, the process returns to step 91 to wait for the copy destination switch 55 to be pressed again. Step 9
If the copy switch 54 is pressed in step 4, the flow advances from step 94 to step 96 to transfer the data of the sensitivity adjustment resistance Re (A) set by the copying without the work, to the memory of the designated sensor module. Then, the routine proceeds to step 97, where it is checked whether or not the mode changeover switch is in the "SET" or "RUN" state. If it is in the "RUN" state, the sensitivity setting is completed only by the teaching without a work, and therefore the normal operation mode is entered. In this case Re set here
The distance Lona with respect to (A) is the set distance in the no teaching. Therefore, in FIG. 9C, this distance Lona
An object can be detected if the detection object 3 passes through it.

Next, the processing for performing presence / absence teaching will be described. FIG. 14A is a graph showing the change of the conductance of the coil with respect to the set distance L to the work in the teaching with and without the work, and FIG. 14B is the value of the sensitivity adjustment resistance (combined resistance) Re and the oscillation stop state. Graphs showing changes in the operating distance L, (c), (d) are diagrams showing the relationship between the sensor head 41 and the detection object 4 at this time. Teaching with / without work is shown in FIG. 14, for example.
As shown in (c), it is used for the purpose of detecting the protrusion 4a protruding toward the proximity sensor in the detection object 4 having a step. In this case, the non-protruding portion of the detection object 4 is first made to face the sensor head 41, and the set mode is set to depress the teaching switch 52 for the first time. The distance between the sensor head 41 and the detection surface of the detection object 4 at this time is L2. Then, the process proceeds to the routine 73 through the steps 71 and 72 described above, and the same processing as the teaching without a work is performed. Using Re (N) obtained in this way, the sensitivity adjustment value in teaching with and without a work is set. The conductance of the coil at this distance L2 is g ₂ . In this case, step 75
Then, without setting the mode changeover switch 53 to "RUN", the protrusion 4a of the detection object 4 is made to face the sensor head 41 and the teaching switch 52 is pushed down as shown in FIG. The distance between the sensor head 41 and the detection surface of the detection object 4 at this time is L3. If the teaching switch 52 is pressed, step 7
The routine proceeds from step 5 to routine 76, and teaching with and without work is executed.

As shown in FIG. 15, the routine 76 for teaching without a workpiece first sets the sensitivity adjusting resistance to Re (0), that is, the minimum value in step 101, as in the routine 73. Then, in step 102, the pointer n is incremented and a new sensitivity adjustment resistor Re (n) is added.
Set. Then, the routine proceeds to step 103, where it is checked whether or not the amplitude at that time is less than or equal to the threshold value. In this way, if it becomes less than the threshold value, the process proceeds to step 104, and the sensitivity adjustment resistance Re (n) at that time is set to Re (E). The conductance of the coil at this distance L3 is g ₃
And Then, the process proceeds to step 65, where the sensitivity adjustment resistance value Re (B) in the teaching with and without the work is set to Re (N).
And Re (E). Re (B) may be a value at the center of these or a value close to one of them.

When this routine 76 is completed, the routine proceeds to step 77, where the mode changeover switch 53 is set to "RU".
It is checked whether the state is "N" or "COPY". If it is in the "COPY" state, the routine proceeds to step 91, where the same copy processing as in FIG. 13 is performed. Then, it is checked whether or not the copying is completed and the status becomes "SET" or "RUN". In the "RUN" state, the presence / absence of an object is determined based on the sensitivity adjustment value Re (B) set by teaching with or without a work. By doing this, Fig. 14 (c)
As shown in, the distance Lonb can be used as a threshold distance to adjust so as to detect only the protrusion 4a of the detection object 4 having a step.

Next, the processing when the positioning teaching is performed will be described. FIG. 16A is a graph showing the change in the conductance of the coil with respect to the set distance L to the work in the positioning teaching, and FIG. 16B is the value of the sensitivity adjustment resistance (combined resistance) Re and the operating distance until the oscillation is stopped. A graph showing a change in L, (c) is a diagram showing a relationship between the sensor head 41 and the detection object 3 at this time. In the positioning teaching, as shown in FIG. 16C, the object is placed near the sensor head 41 at a position Lonc requiring positioning. Then, the teaching switch 52 is pressed. Then step 7 through step 71, 72
3, the sensitivity adjustment resistance Re gradually increases from the minimum value as described above, and the sensitivity adjustment resistance Re (N) is set. At this time, teaching without a work is once performed, but the teaching switch 52 is continuously depressed. Then, in the routine 76, the sensitivity adjustment resistance Re gradually increases from the minimum value again as shown in FIG. 15, and the resistance value at the time when the oscillation stops becomes Re (E). Then, the sensitivity value Re (B) is set in the teaching with or without the work, but in step 78, the teaching switch 52 is turned on again. In this way, the process proceeds from step 78 to step 79 to perform positioning teaching. The sensitivity adjustment value Re (C) in this positioning teaching is
Re set in step 104 of routine 76
(E) is used as it is. The conductance of the coil at this time is g ₄ . Then, since the sensitivity adjustment in the positioning teaching is completed, the routine proceeds to step 80, where the mode changeover switch 53 is set to the "RUN" mode or the "COP".
Check to see if it is in Y mode. "COP
If it is the "Y" mode, the process proceeds to FIG. 13 and the copy process is performed.
If it is the "RUN" mode, the positioning teaching is finished and the processing is finished. By doing so, the distance Lonc from the sensor head 41 to the detection object 3 in FIG.
Will be set as the threshold value. Therefore, it is possible to perform processing such that the detected object is approached from the distance toward the sensor head 41 and the object can be detected at the set position. Where C
The PU 47 achieves the function of the threshold value setting means 47c that sets the threshold value by performing the teaching without work, the teaching without work and the positioning teaching in routines 73, 76 and step 79, respectively.
1 to 97, the function of the threshold transmitting means 47d for transmitting the threshold data to other sensor modules is achieved.

Next, the processing of the sensor module when writing data from another sensor module will be described.
FIG. 17 is a diagram showing an interrupt process of the sensor module.
If a write command is input via the sensor module in this figure, the memory 56 is set to the write state in step 112, and the process is terminated. This corresponds to the write state setting of the memory in step 92 shown in FIG. If the reset key is pressed in step 95 of FIG. 13, a reset command for canceling the written state is transferred in step 95. When the reset command is transferred in step 113 in FIG. 17B, the process proceeds to step 114 to perform an interrupt process, cancel the write state, and end the process. When the copy data transfer process is performed in step 96 of FIG. 13, the copy command and data are first transferred. Therefore, if the copy command is transferred, the transferred threshold value is written in the memory 56 and the process is terminated (step 116). Here, the CPU 47 achieves the function of the threshold value receiving means 47e for writing the transferred data by putting the memory in the write state based on the command transferred from the other sensor module in steps 111 to 116.

In the embodiment described above, the sensor module 40
Although the teaching is performed by operating the switch provided on the panel surface 44 of the above, the threshold value is transferred to another sensor module. However, the teaching or copying process is performed by using the switch of the remote console 60 shown in FIG. You can also do it. In this case, the module to be taught is selected in advance by the module selection switch 61, and thereafter, the teaching process is performed in the same manner as the teaching in each sensor module described above. Then, by appropriately setting the copy destination switch 67, the obtained threshold value of the module selection switch is transferred to another sensor module. Remote console 6
When 0 is used, the teaching process can be performed at a position distant from the sensor unit, which is easy to use for processes such as teaching with or without work and positioning teaching.

Although the proximity sensor is shown as the sensor module in this embodiment, it can be used as a photoelectric sensor. FIG. 18 is a block diagram showing a sensor module 40A for a photoelectric sensor. In this case, the oscillator circuit 48, the sensitivity adjustment circuit 49, and the detection circuit 50 are replaced with the configuration shown in FIG.
As shown in FIG. 8, a light projecting drive unit 120 and a light receiving unit 121 are provided. The light projecting drive unit 120 drives the light projecting element of the head based on a predetermined timing signal from the CPU 47. A light projecting element and a light receiving element are provided in the sensor head 41A, and the output of the light receiving element is given to the light receiving section 121 in the sensor module 40A. The light receiving section 121 is connected to the light receiving element of the sensor head 41A and changes the amplification factor based on the output obtained from the CPU 47 to amplify the received light signal. The amplified output is an A / D conversion section in the CPU. 47a. Other configurations are similar to those of the sensor module 40 for the proximity sensor. Although this photoelectric sensor type sensor module performs teaching processing in the same manner as the proximity sensor, it is assumed that only teaching without work and teaching with or without work is performed, and positioning teaching is not performed.

Next, a third embodiment of the present invention will be described. In the present embodiment, by designating the copy source, a threshold value similar to the threshold values set in other sensor modules is set. In this case, the sensor module is provided with a copy source switch 55A (not shown) in place of the copy destination switch 55. Similarly, the remote console is also provided with a copy source switch 67A instead of the copy destination switch 67. The copy source switch is the same as the copy destination switch 55 except that there is no "ALL" key, and other sensor modules can be specified individually. FIG. 19 is a flowchart showing the copy processing in the sensor module. When the operation starts in this figure,
First, at step 131, it is checked whether or not the mode changeover switch 53 is set to the "COPY" mode. If the "COPY" mode has not been set, the same processing as in FIG. 10 is performed. However, in FIG. 10, it is assumed that the copying process to another sensor module is not included.

If the mode changeover switch 53 is set to "COPY", the process proceeds to step 132 and the copy source switch 55A waits for the designation of the copy source. If the copy source is designated, the process proceeds to step 133 to wait for the copy switch 54 to be pressed. If the copy switch 54 is pressed, the process proceeds to step 134 to check whether the threshold data is set in the memory of the copy source sensor module. To check. Step 135 if not set
Proceed to and display the error that copying is not possible. If the threshold value has been set, the process proceeds to step 136 to put the memory in the written state. Then, in step 137, a data transfer command is output to the copy source module. When the data is transferred from the copy source, the received data is set in the memory 56 as a threshold (step 138). Then, in step 139, the change of the mode changeover switch is waited for, and when the state becomes "RUN", the teaching process is ended and the process proceeds to the normal process. In this way, the threshold value can be set by taking in the threshold values set in other modules without performing teaching in each module.

Next, the processing when the copy destination module is designated by the remote console will be described. When the operation of the flow chart on the sensor unit side in the flow chart shown in FIG. 20 is started, it is first checked whether or not the mode changeover switch of the remote console is in the "COPY" mode. If the mode is the "COPY" mode, the routine proceeds to step 142, where the module selection switch 61 waits for the designation of the target sensor module. Copy switch 68 when a module is selected
If the copy switch is turned on, the memory of the selected sensor module is set to the writing state as shown in FIG. Then, the process proceeds to step 145, and the copy source switch 67A waits for the designation of the copy source sensor module. If the copy source is specified, the process proceeds to step 146 to check whether the threshold data is set in the copy source module. Step 1 if threshold data is not set
Proceed to 47 to display an error. If the threshold data is set, the memory is set to the writing state, and step 14
In step 9, the data transfer command is sent to the copy source module. Then, the data is transferred from the copy source module to the copy destination and written in the memory of the module (step 150). When the data transfer process is completed in this way, it waits in step 151 to see if the mode selector switch has been switched to the "RUN" state, and if so, the process ends. In this way, the sensor module side can also transfer the data by designating the copy source.

In this embodiment, the sensitivity adjusting resistor Re connected to the emitter of the transistor Q2 of the oscillation circuit shown in FIG. 7 is replaced with a parallel resistance group and a switch circuit, and the resistance value is changed by this. It goes without saying that the resistance value can be connected in series and short-circuited by the switch circuit. Furthermore, the sensitivity is adjusted by changing the resistance value of the emitter resistor.
Alternatively, the resistors R6 and R7, which determine the feedback current of the current mirror circuits of Q3 and Q4, may be changed by a switch signal.

[0041]

As described above in detail, according to the present invention, when a threshold value is set for a specific amplifier separation type sensor in a sensor system in which a plurality of amplifier separation type sensors are arranged, the same threshold value as that threshold value is set. Can also be transferred to another amplifier-separated sensor. Therefore, even if there are many sensors, if the same threshold value is sufficient, it is not necessary to set the threshold value for each sensor, and the threshold setting procedure can be greatly simplified. Further, even if the sensor section and the amplifier section are separated and installed in a state where the correspondence is unclear, the sensitivity setting of one amplifier separation type sensor is sufficient, and therefore the effect that the adjustment work can be easily processed is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a sensor module of an amplifier separation type sensor according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a connected state of the sensor system according to the present embodiment.

FIG. 3 is a perspective view showing a configuration of a sensor unit according to this embodiment.

FIG. 4 is a block diagram showing an electrical configuration of a power supply unit and a CPU unit used in the sensor system according to the present embodiment.

FIG. 5 is a block diagram showing an electrical configuration of a sensor unit according to the present embodiment.

6A is a perspective view showing a sensor module for a proximity sensor according to the present embodiment, and FIG. 6B is a front view thereof.

FIG. 7 is a circuit diagram showing a configuration of an oscillation circuit and a sensitivity adjustment circuit of the sensor module according to the present embodiment.

FIG. 8 is a front view showing the external appearance of the remote console used in this embodiment.

FIG. 9A is a graph showing a conductance of a coil with respect to a work set distance, and FIG. 9B is a graph showing a change in a value of a sensitivity adjustment resistance Re for starting / stopping oscillation with respect to an operating distance;
FIG. 6C is a diagram showing a relationship between a proximity sensor and a detection object in the non-teaching.

FIG. 10 is a flowchart showing the entire teaching process of this embodiment.

FIG. 11 is a flowchart showing an operation of teaching without a work according to the present embodiment.

FIG. 12 is a graph showing the amplitude of the oscillation circuit with respect to the set distance L of the proximity sensor to the work.

FIG. 13 is a flowchart showing copy processing of this embodiment.

FIG. 14A is a coil conductance with respect to a work set distance, and FIG.
A graph showing a change in the value of the sensitivity adjustment resistance Re that stops,
(C), (d) is a figure which shows the relationship between a proximity sensor and a work in teaching with or without a work.

FIG. 15 is a flowchart showing a teaching process in teaching with or without a work.

16 (a) is a coil conductance with respect to a work set distance, and FIG.
A graph showing a change in the value of the sensitivity adjustment resistance Re that stops,
(C) is a diagram showing a relationship between a proximity sensor and a detection object in positioning teaching.

FIG. 17 is a flowchart showing an interrupt process of a copy destination sensor module according to the present embodiment.

FIG. 18 is a block diagram showing a configuration of a sensor module according to a second embodiment of the present invention.

FIG. 19 is a flowchart showing copy processing of the sensor system according to the third embodiment of the present invention.

FIG. 20 is a flowchart showing copy processing using a remote console of the sensor system according to the third embodiment of the present invention.

FIG. 21 is a schematic diagram showing a usage state of a conventional amplifier separation type sensor.

[Explanation of symbols]

 1 Sensor System 1a Power Supply Unit 1b CPU Unit 11 Sensor Unit 12-1 to 12-3 Slot 40, 40A Sensor Module 41 41A Sensor Head 47 CPU 47a A / D Converter 47b Discriminating Means 47c Threshold Setting Means 47d Threshold Transmitting Means 47e Threshold Receiving means 48 Oscillation circuit 49 Sensitivity adjustment circuit 50 Detection circuit 51 Setting section 52 Teaching switch 53 Mode selection switch 54 Copy switch 55 Copy destination switch 120 Emitter drive section 121 Light receiving section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H03K 17/78 B 17/945 B

Claims (7)

[Claims] 1. An amplifier-separated sensor in which a sensor head including a detection element and a signal processing unit connected to the sensor head are separated, and a transmitter circuit for driving the sensor head, and a sensor circuit for driving the sensor head. A receiving circuit that receives a signal, a determination unit that determines the presence or absence of an object by comparing the input from the receiving circuit with a threshold value, and the threshold value for the presence or absence of an object is set based on the input from the receiving circuit and the teaching input. Threshold value setting means, threshold value transmitting means for transmitting the threshold value set by the threshold value setting means to another amplifier separation type sensor, and threshold value data transmitted from another amplifier separation type sensor, and the threshold value of the judging means. An amplifier separation type sensor, comprising: 2. A sensor unit having a slot to which a plurality of sensor modules are detachably attached, an interface circuit section with each of the sensor modules, and a data transfer means, and a sensor module attached to the sensor unit. In the sensor system, the sensor module includes a sensor head including a detection element, a signal processing unit connected to the sensor head, and a transmission circuit for driving the sensor head, and a signal from the sensor head. A receiving circuit for receiving the object, a discriminating means for discriminating the presence or absence of an object by comparing the input from the receiving circuit with a threshold value, and a threshold value for setting the threshold value of the object presence or absence based on the input from the receiving circuit and the teaching input. The threshold value set by the setting means and the threshold value setting means is set by another sensor module. And a threshold value transmitting means for transmitting the threshold value data transmitted from another sensor module and setting the threshold value data as a threshold value of the discriminating means. Sensor system. 3. The sensor system includes a remote console connected to the sensor unit according to claim 2 via a cable, wherein the remote console includes a sensor module mounted in a slot of the sensor unit. A first selection switch to select, a mode selection switch to select a sensitivity setting mode and an operation mode, a teaching switch to input timing when setting a threshold, and a second selection switch to specify a sensor module to which a threshold is to be transmitted. The amplifier-separated sensor system according to claim 2, characterized by comprising: 4. The sensor head has a detection coil, and the transmission circuit of the signal processing unit is an oscillation circuit connected to the detection coil and a sensitivity adjustment circuit for changing the oscillation intensity thereof. The amplifier-separated sensor according to claim 1, wherein the reception circuit of the processing unit is a detection circuit that detects the output of the oscillation circuit. 5. The sensor head has a light projecting element and a light receiving element, and the transmission circuit of the signal processing section is a light projecting drive section that drives the light projecting element of the sensor head. The amplifier separation type sensor according to claim 1, wherein the receiving circuit of the part is a light receiving part connected to a light receiving element of the sensor head. 6. A method of transferring a threshold value in an amplifier-separated sensor system according to claim 2, wherein the sensor module of the copy destination is selected based on the threshold value of the sensor module that is already set, and the set threshold value is set. A threshold value setting method for an amplifier-separated sensor system, which is characterized in that the threshold value is transferred to a selected module and the threshold value sent from another sensor module is written in the determination means of the sensor module. 7. The threshold value transfer method in the amplifier-separated sensor system according to claim 2, wherein a sensor module for which a threshold value has already been set is selected as a copy source sensor module, and the threshold value of the selected sensor module is set. A threshold value setting method for an amplifier-separated sensor system, which is characterized in that the threshold value is transferred to a designated sensor module, and the threshold value sent from the selected sensor module is written in the discrimination means of the sensor module.