JP3409242B2 - Sensor device remote control method, sensor control system, and sensor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller such as a programmable controller, a sensor control system connected to the controller, a sensor device and a remote control method thereof.

[0002]

2. Description of the Related Art A number of sensor devices for detecting passage of articles are installed on an assembly and transportation line of a factory or the like, and signals from these sensor devices are read to switch transportation routes and various processing devices. A control device such as a programmable controller is connected to operate the above. In such a control system, conventionally, when setting a threshold value for detecting an object of each sensor, a variable resistor or the like is operated by each sensor. However, as the sensor becomes multifunctional, it becomes difficult to set the threshold value at the sensor position,
There is a desire to switch the function of the sensor or set a threshold value from a programmable controller connected to the sensor. Normally, when electrically connecting a sensor and a programmable controller etc. and transmitting signals to each other,
It is conceivable to provide one input / output circuit or input / output line for one function. In order to perform mutual communication with a general-purpose unit, RS232 must be installed on the programmable controller side.
It is necessary to provide a dedicated communication unit such as C, and also to provide an interface and a communication driver corresponding to this communication unit on each sensor side.

[0003]

As described above, in the conventional method of allocating one external input line to a sensor for one function, if the number of functions is increased, more input circuits and input lines are needed, and It had the drawbacks of hindering downsizing, cost reduction, and wiring saving for the entire system. Also RS2
When a serial communication system such as 32C is used, it is necessary to provide a communication unit compatible with serial communication on the side of the sensor and the programmable controller, and it is difficult to reduce the size of the sensor. Also, the programmable controller has a maximum of 0.
Since a time error of 1 second occurs, it is difficult for the sensor side to synchronize with this, and effective remote control cannot be performed.

The present invention has been made to solve such conventional problems, and controls a sensor device by using a ladder program which is widely used to realize a control function of a programmable controller or the like. The signal is generated so that it can be applied to the current controller system.

[0005]

The invention according to claim 1 of the present application is a remote control method in a remote control system having a controller capable of generating an arbitrary signal by a ladder program and a sensor device connected to the controller. By sending a serial signal generated by a ladder program in the controller as a control signal for the sensor device,
It is characterized in that the sensor device is controlled. Here, the control signal of the sensor device is a signal for changing the operating condition of the detection operation of the sensor device.

According to a second aspect of the present invention, in a sensor control system having a controller capable of creating an arbitrary signal by a ladder program and a sensor device connected to the controller, the controller is generated by the ladder program. A serial signal is output as a control signal of the sensor device, and the sensor device has a function of identifying a control signal transmitted from the controller based on the time and executing the control content. It is a feature. Here, the control signal of the sensor device is a signal for changing the operating condition of the detection operation of the sensor device.

According to a third aspect of the present invention, in the sensor control system according to the second aspect, the control signal has a rising edge of the signal and a signal of a constant time width following the rising edge of the signal as a start bit, and a predetermined value following the start bit. It is characterized in that it is composed of a serial signal of a plurality of bits in which a predetermined number of bits are consecutive with the time width as a unit. Here, the control signal of the sensor device is a signal for changing the operating condition of the detection operation of the sensor device.

According to a fourth aspect of the present invention, a sensor means having a function of detecting an external state, an input means for inputting a signal from the outside, and a constant time width following a rise of the signal input from the input means are provided. Control signal identification means for identifying a control signal transmitted after receiving a start bit and a serial signal of a predetermined number of bits following the start bit and receiving a signal of a reception time of a predetermined number of bits, and executing control contents of the identified control signal And a control means for controlling the operation.

Here, the function of detecting the external state of the object is to detect the presence or absence of the object or measure the distance to the object, or to measure the physical quantity such as external pressure or weight of weight, speed, temperature, light quantity or color. It shall have the function of detecting information, light wavelength components, etc. Further, the control signal is a signal for changing conditions for detection such as changing the detection threshold of the sensor means.

[0010]

1 is a schematic diagram showing the configuration of a sensor device and a programmable controller according to an embodiment of the present invention. The programmable controller 1 is usually connected to a plurality of sensor devices, processing devices, etc., and has a function of controlling these devices by a ladder program. Here, an example in which one sensor device 2 is connected is shown. The programmable controller 1 has a programmable controller main body, an output unit, and an input unit, and transmits a remote control signal to the sensor device 2 via the output unit. Further, it receives a detection signal or an answerback signal from the sensor device 2 via the input unit. On the other hand, the sensor device 2 has a sensor function such as a photoelectric sensor or a proximity sensor for detecting an object, and receives a remote control signal from the programmable controller and outputs an answerback signal according to this embodiment. It has an external input unit and an external output unit for operating.

FIG. 2 is a block diagram showing a detailed configuration of the programmable controller 1 according to this embodiment.
In this figure, the programmable controller 1 has a command input section 11, a ladder program creating means 12, a control signal output section 13, and an output unit 14, and distinguishes the input unit 15 that receives a signal from the sensor device and the received signal. Signal identifying unit 16 and answer back confirmation unit 1
7, a switching unit 18, a measurement signal processing unit 19, and a display unit 20. The command input unit 11 is composed of a keyboard or the like, and is used when a ladder program is input or the program is executed. The ladder program creating means 12 includes an instruction content identification unit 12a, a code signal creation unit 12b, a code storage unit 12c, and an internal timer 12d, and identifies the instruction content input from the instruction input unit 11 to identify the ladder program. The code is generated and the code is stored. Also, based on a program start signal from the instruction input unit 11, a ladder program is executed from the code stored in the code storage unit 12c in advance, and a control signal is generated and output using the internal timer 12d. . The control signal output unit 13 outputs the control signal thus generated to the sensor device 2 side via the output unit 14. Further, the control signal output unit 13 outputs a switching signal to the switching unit 18, and switches so that the output of the signal identifying unit 16 is not transmitted to the measurement signal processing unit 19 until answer back confirmation processing. The input unit 15 also receives a detection signal and an answerback signal, which are signals from the sensor device 2, and outputs them to the signal identifying section 16. The signal identifying section 16 identifies the measurement signal indicating the presence or absence of an object and the answerback signal. When an answer back signal is sent, the answer back signal is output to the answer back confirmation unit 17. The answer-back confirmation unit 17 displays the state of an answer-back signal of normal termination and switches the switching unit 18 to the measurement signal side. The measurement signal processing unit 19 processes an object detection signal or the like from the sensor device.

On the other hand, as shown in FIG. 3, the sensor device 2 has an external input section 31, a control signal input detection section 32, a control signal time measuring section 33, a control signal identifying section 34 and a control section 35. The external input unit 31 receives a signal from the programmable controller 1, and the control signal input detection unit 32 extracts a rising timing signal and a falling timing signal of the input. The control signal time measuring unit 33 measures the time of the control signal from the timing, and the control signal identifying unit 34 identifies the content of the control signal based on this measurement time. Further, the control unit 35 has a function of executing control contents in accordance with the identified control signal, and for example, switches each bank held in the memory unit 36 or changes the threshold value thereof. When the control section 35 completes this operation, it outputs an end signal to the answerback signal creating section 37. The answer-back signal generation unit 37 generates an answer-back signal in response to normal termination of processing of the operation content or abnormal termination. Further, the sensor device 2 has a sensor section 38 for detecting an external state such as the presence or absence of an object, a sensing processing section 39, and a measurement signal output section 40. The sensor unit 38 and the sensing processing unit 39 determine the presence or absence of an object according to the threshold value set by the control unit 35, and the output thereof is given to the measurement signal output unit 40. The measurement signal output unit 40 generates a detection signal such as the presence / absence of an object based on the signal from the sensing processing unit 39, and supplies it to the switching unit 41. The switching unit 41 switches the signal output to the programmable controller 1 to either the detection signal or the answerback signal, and outputs the signal via the external output unit 42.

Next, the specifications of the control signals used in this embodiment will be described. Programmable controller 1
The control signal output from the sensor device 2 is shown in FIG.
As shown in, the start bit is followed by a 4-bit NRZ
The control signal is continuously output again after a certain period of time has elapsed after the end of the control signal.
Here, the start bit is a bit that becomes H level for a certain time width after the signal rises, and here, this time width is set considering the error of 0.1 second which is the maximum error based on the cycle time of the programmable controller. 0.3 seconds. In the figure, (seconds) is omitted. Also, a time of 0.3 seconds is allocated to each bit of the control signal transmitted after the start bit,
With this time width, for example, a 4-bit control signal is continuously generated. 5 and 6 show examples of control signals, control codes and functions.

For example, when the sensor device is a photoelectric sensor, the photoelectric sensor has a bank switching function so that different threshold values can be set in advance for different detection objects, and the control transmitted from the programmable controller 1 is performed. As shown in FIGS. 5 and 6, the code has No. 1 to
No. Allocate 15 functions. That is, the control code "000
As shown in FIG. 5, the "0" is such that the L level continues for 1.2 seconds after the start bit, whereby the function of the sensor device is switched to the bank 1. Control code "10
"00" is a signal which is at H level for 0.6 seconds including the start bit, and is kept at L level for 0.9 seconds thereafter, whereby the bank 2 is switched. Similarly, switching to banks 3 and 4, teaching, thresholds 1 to 8
To the sensor device 2 from the programmable controller 1 via the above-mentioned input / output unit.
FIG. 4B shows a control signal from the programmable controller to a certain sensor device. Bank 1 is selected between times t ₁ and t ₂ , and then bank 1 is selected between times t _{3 and} t ₄ . Indicates that a teaching signal has been input.

An example of bank switching will be described here. In the case where the sensor device is a color mark sensor that detects the colors of a plurality of objects, the threshold value changes according to the color to be detected. Therefore, for example, light-emitting diodes of three colors of red, green, and blue are coaxially time-divisionally projected through a light-projecting lens, the reflected light is separated and detected by a photodiode, and the color is detected by the ratio. You can The thresholds are registered in advance in banks 1 to 4 according to the color to be detected, and different colors can be detected with the optimum thresholds by switching these banks. Further, when the teaching mode is set in a state where the object is arranged at a predetermined position in order to set the threshold value of the sensor device, a process of setting the threshold value so that the object can be surely detected from the light receiving level at that time is performed.

FIG. 7 shows the above-mentioned No. It is a figure which shows the ladder program for producing | generating the control signal of 0-15 with the programmable controller 1. In this figure, the symbol "0
"0000" indicates an input relay symbol, and "0"
“0100” indicates an output relay symbol. "05000", "05001", and "05002" are other internal auxiliary relays, and "TIM000" and "TIM0".
"01" and "TIM002" indicate internal timers.
Here, the control function No. Timers TIM000, TIM001, TIM002 for outputting control signals 0 to 15
The setting values #XXXX, #YYYY, #ZZZZ are shown below.

[Table 1]

For example, No. When outputting 10 control signals, "TIM000" displays 0003 (0.3s), "TIM".
001 "is set to 0006 (0.6s), and" TIM002 "is set to 0006 (0.6s). In this way, if the input relay "00000" is turned on based on this ladder program, the internal relay "50000" will be output according to the input timing as shown in the time charts of FIGS. 8 (a), (b) and (c). Self-holds and the timer "T
The IM000 "operates and the internal relay" 05001 "holds itself. In addition, the timer "TI
M001 ”operates, and a timer“ TIM002 ”operates 0.6 seconds after that. Therefore, the internal relays “5000”, “5001”, “5002” operate like the time chart shown in the figure, and the output relay “0010”.
From "0", "0001" is obtained following the start bit as shown in FIG. Other control signals can be similarly generated by setting only the timer value of the internal timer.

Next, the operations of the programmable controller 1 and the sensor device 2 will be described with reference to the flowchart of FIG. When the programmable controller 1 starts to output the control signal, first, the function of the ladder program created in advance in step S1 is selected and the control signal is output. This is set by switching the timer value in the ladder program described above. The control signal of any of 1 to 15 can be output. During the output of the control signal in step S2, the measurement result obtained from the sensor device 2 is set to the invalid state, and when the output of the control signal ends, the end of the output is notified (step S3). Next, a standby state waiting for an answer back from the sensor device 2 is set (step S4). Then, when the answer back signal is received in step S5, it is determined whether or not the operation is normally completed. If it is normal termination, then the signal obtained from the sensor device is validated as the measurement result, and the output processing of the control signal is terminated (step S6). If the answer back signal is not normally terminated in step S5, step S7
At, error processing is performed and the processing ends.

On the other hand, when the sensor device 2 starts to operate,
First, in step S11, it is detected whether or not a control signal is input. If the control signal is not input, the measurement operation is continued (step S12). When the control signal is input as shown in FIGS. 4 and 5, the start bit is input and the signal rises. Therefore, when the rise is detected in step S11, the process proceeds to steps S13 and S14 to interrupt the measurement process and measure the time of the control signal. Then, in step S15, a fixed time, that is, 1.5 seconds set as the output time of the control signal and 1.8 seconds obtained by adding 0.3 seconds which is the maximum error of the programmable controller 1 expected from this output have elapsed. Or whether the end of the control signal has been sent. When this time elapses or the transmission of the control signal ends, step S
At 16, the control signal is discriminated. That is, the control signal is discriminated on the basis of the number of pulses and the ON time and OFF time of the pulse in the above 1.8 seconds. And step S1
In step 7, the control content corresponding to the control signal is executed. For example, in FIG. In 1 to 4, bank switching processing is performed and N
o. At 5, the teaching mode is entered. Also, N in FIGS.
o. In 6 to 11, change processing to the set threshold value is performed.
Then, the process proceeds to step S18, and it is determined whether or not these processes are normally completed.
An answerback signal indicating normal termination is output at 9, and an answerback signal indicating abnormal termination is output at step S20 if not normally terminated. And step S
In 21, the measurement process is started again and the process returns to step S11.

In this way, the sensor device can be controlled by using the ladder program creation / execution processing software of the programmable controller as it is. Further, if the control signal specifications are set in consideration of the output error of the programmable controller as in this embodiment, the response time of the system can be optimized. In this embodiment, the ladder program is created by the programmable controller. However, even if the ladder program cannot be created, a function that can execute the ladder program and output an arbitrary serial signal is sufficient. Further, in this embodiment, the sensor device is controlled by the programmable controller, but another type of controller may be used as long as it has a function of creating a ladder program and outputting a serial signal.

[0021]

As described above in detail, according to the present invention, a control signal can be transmitted in a system in which a controller and a sensor are connected, and a remote control system for the sensor can be constructed. it can. Further, since the controller outputs the control signal to the sensor by the ladder program, the remote control system can be constructed without depending on the controller model, function and manufacturer. Further, since the ladder program for outputting the control signal once created can be used as it is in other sensor devices to which this control signal is applied, the function of the sensor device can be easily changed, and the number of man-hours for system construction can be increased. Can be reduced. Further, the control signal output ladder program can be provided to the user by a storage medium or a document, and the effect of reducing the user's program preparation work can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall system of a remote control system according to the present embodiment.

FIG. 2 is a block diagram showing a configuration of a programmable controller according to the present embodiment.

FIG. 3 is a block diagram showing a configuration of a sensor device according to the present embodiment.

FIG. 4 is a time chart showing a control signal format and its signal example according to the present embodiment.

FIG. 5 is a diagram (part 1) showing an example of functions of a control signal, a control code, and a sensor according to the present embodiment.

FIG. 6 is a diagram (part 2) showing an example of the functions of the control signal, the control code, and the sensor according to the present embodiment.

FIG. 7 is a diagram showing an example of a ladder program of the remote control system according to the present embodiment.

FIG. 8 is a time chart showing the operation of each relay and the generated control signal when the ladder program according to the present embodiment is executed.

FIG. 9 is a flowchart showing an operation of the remote control device according to the present embodiment.

FIG. 10 is a flowchart showing the operation of the sensor device of the remote control system according to the present embodiment.

[Explanation of symbols]

1 programmable controller 2 sensor device 11 Command input section 12 Ladder program creation means 13 Control signal output section 14 Output unit 15 Input unit 16 Signal identification section 17 Answerback Confirmation Section 18 Switching unit 19 Measurement signal processing unit 20 Display 32 Control signal input detector 33 Control signal time measurement unit 34 Control signal identification section 35 control unit 36 memory 37 Answerback Signal Creation Department 38 Sensor section 39 Sensing processing unit 40 Measurement signal output section 41 Switching unit

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05B 19/02-19/05

Claims (4)

(57) [Claims] 1. A remote control method in a remote control system having a controller capable of creating an arbitrary signal by a ladder program and a sensor device connected to the controller, wherein the serial generated by the ladder program by the controller. A remote control method for a sensor device, wherein the sensor device is controlled by sending a signal as a control signal for the sensor device. 2. A sensor control system having a controller capable of creating an arbitrary signal by a ladder program and a sensor device connected to the controller, wherein the controller outputs a serial signal generated by the ladder program to the sensor device. The sensor device outputs a control signal, and the sensor device has a function of identifying a control signal transmitted from the controller based on its time and having a function of executing the control content. Control system. 3. The control signal comprises a start bit which is a signal of a rising edge of a signal and a fixed time width following the rising edge of the signal, and a plurality of bits which are consecutive with a predetermined number of bits in units of a predetermined time width following the start bit. The sensor control system according to claim 2, wherein the sensor control system comprises a serial signal. 4. A sensor means having a function of detecting an external state, an input means for inputting a signal from the outside, a start bit having a constant time width following a rising edge of the signal input from the input means, and a predetermined value following the start bit. Control signal identifying means for receiving a serial signal of a bit number and identifying a control signal sent after receiving a signal of a receiving time of a predetermined bit number; and a control means for executing a control content of the identified control signal,
A sensor device comprising: