JP3297541B2 - Programmable controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller for performing sequence control of various types of processing equipment and mechanical equipment, and more particularly to an input / output unit for receiving an external signal and driving an external load, and an input / output unit. The present invention relates to a structure suitable for displaying and electrically isolating data transmitted to and from an arithmetic control unit that performs arithmetic processing based on output data.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 5, a programmable controller (hereinafter abbreviated as a PC) transmits an electric signal between an arithmetic control unit (hereinafter abbreviated as a CPU) 8 and an input / output unit 7 by an external device. Photo coupler 4 on the signal input side
Is used for electrical insulation, an output element 6 is used on the output side, and protective measures are taken to prevent noise from directly entering the input / output unit 7. However, stray capacitance existing between the wiring patterns of the printed circuit board and in the input / output wiring induces noise generated from an external load, for example, an electromagnetic switch, and enters the input / output unit 7. This noise may adversely affect data transmission between the input / output unit 7 and the CPU 8 or may cause the CPU 8 to malfunction via the connector 5 for supplying a DC 5 V system voltage to the CPU 8.

[0003] Recently, small PCs frequently requested by users.
In this case, since the distance between the output unit and the wiring pattern of the data bus is short, this tendency appears remarkably structurally.
In addition, with the demand for miniaturization of the PC, the miniaturization of each of the constituent elements has been progressing. However, as shown in FIG. 5, the light emitting element 1 for displaying information outside has a space for arranging the LEDs. This is necessary, and in particular, when trying to reduce the area of the display panel provided on the front surface, the occupied portion of the LED is an obstacle to the reduction.

[0004]

In the above prior art,
Since the size of the PC is reduced and the distance between the input / output unit 7 and the wiring pattern of the CPU 8 is reduced, noise resistance is reduced. Also, in order to realize miniaturization, it is important to effectively utilize the space near the display unit. The present invention provides a data transmission structure between an input / output unit and a CPU, which is effective for providing electrical insulation without using a connector, eliminating noise generation factors associated with miniaturization, and utilizing display space of a display unit. It is intended to provide.

[0005]

Means for Solving the Problems The following two points are considered as requirements corresponding to the above-mentioned problems.

(1) A light emitting element, for example, an LED is made to emit light at an input section for inputting an external input signal, and the external input signal is transmitted to a light receiving element, for example, a phototransistor.

(2) Based on the transmitted input data,
The external output signal processed by the CPU is transmitted to the light receiving element while being displayed by the light emitting element. That is, the present invention provides a first substrate including an input / output unit including an input circuit for capturing an external signal and an output circuit for driving an external load, as described in claim 1 of the claims;
A second substrate, which is provided so as to be insulated and separated from the first substrate by a light transmitting means, and further includes an arithmetic control unit for performing arithmetic processing based on output information from the input / output unit. /> a to pulp logs llama logic controllers, said light transmitting means, second phototransistor the input information and the first phototransistor for operation control to output for transmitting the input information from the first substrate and, , Has an input / output LED,
A display unit for externally displaying input / output information by the light transmission unit , wherein the programmable controller
A programmable controller , wherein an external display is provided by a display unit, and a plurality of the programmable controllers can be interconnected via an optical cable connected to the display unit.

[0008]

With the above arrangement, the input / output unit and the CPU take in an external input signal and transmit an output signal to the outside, and output the information by the light emitting element and the light receiving element of the display unit without using a connector. In addition, since the input / output unit and the CPU are electrically insulated from each other, a structure can be provided in which noise entering from the input / output unit does not enter the CPU.

[0009]

【Example】

<Embodiment 1> Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an outline of the external appearance of a programmable controller of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a block diagram showing a basic structure of the present invention. 2 and 3, information from outside is taken in as an external input signal via the input circuit 20, and the input display LED 12 is caused to emit light based on the input of this signal. This light emission signal is sent only by the input LED cover 14 to the display section of the main body cover 11 and the phototransistor 15 for calculation data input, so that data transmission and external display are performed simultaneously. The data fetched by the input phototransistor 15 is processed in the arithmetic circuit 21 of the CPU board 19, and the result of the processing causes the output display LED 13 to emit light as external output data. This optical signal is sent to the display unit 25 on the main body cover 11 and also sent to the control data input phototransistor 16 via the light guide tube 17. The data taken in by the control data input phototransistor 16 is processed by the output circuit 22 of the I / O board 18 to drive an external load. Input circuit 20 and output circuit 2 shown in FIG.
Reference numeral 2 denotes an input / output unit constituted by an independent I / O board 18 as a unit, and an arithmetic circuit 21 is independently formed on a CPU board 19. The first substrate according to claim 1 corresponds to the I / O plate 18 of the embodiment, and the second substrate corresponds to the CPU plate 19 of the embodiment. That is, I / O board 1
8 and the CPU board 19 are structured so as to transmit data by optical signals, so that they are completely electrically insulated. As in the above embodiment, PC
The input display LED 12 is caused to emit light based on the input signal to the
LE for transmitting data to U-plate 19 and displaying the calculation result
D13, the control data input phototransistor 6
Is transmitted to the I / O board 18 and output by the output circuit 22. A phototransistor can capture only light of a specific wavelength, and can emit external light, for example,
It is also effective in preventing malfunction due to natural light or lighting. The light transmission means according to claim 1 is, for example,
The input display LED 12 and output display LED 13, the input LED cover 14, the operation data input phototransistor 15, the control data input phototransistor 16, and the like in the above embodiment correspond to this.

<Embodiment 2> FIG. 4 is a view showing Embodiment 2 of the present invention. As shown in FIG. 4, input / output information is transmitted using an optical cable 26. That is, by transmitting the input / output information via the optical cable 26 connected to the display unit 25, it becomes possible to exchange information with another PC installed at a remote place. A part of the optical signal information by the LED displayed on the display unit 25 is further transmitted to a remote place via the optical cable 26, and this input / output information is received by the PC at the remote place.
That is, calculation and control can be executed for a plurality of PCs. As a result, a link system for information transmission for configuring a distributed control system can be realized. Programmable controller a installed at a remote location
And b (hereinafter abbreviated as PCa and PCb).
The information input at a is input to the I / O board 18 via the input circuit 20.
In addition to transmitting information to the CPU board 19 through the light guide tube 17, the optical signal from the LED is directly transmitted to the display unit 25 at the top. A part of the light signal by the LED is guided to the optical cable 26 and further transmitted to a remote PCb. PCb
Then, the optical signal is received by the CPU board 19, and arithmetic processing and input / output control are performed. Similarly, the optical signal output from PCa is transmitted to PCb by the optical cable 26, and the Cb of PCb is transmitted.
This is received by the UP board 19 and arithmetic processing and input / output control are performed in the same manner as the input signal. That is, the function of the link system that receives the input / output information of the PCa by the PCb and arithmetically controls the information can be configured.

[0011]

According to the present invention, the input / output unit and the CPU
Can be electrically insulated, preventing the occurrence of noise that may be a concern with the downsizing of the PC, and simultaneously transmitting input / output information and externally displaying the input / output information on the display unit. it can. Also, by mutually connecting a plurality of programmable controllers using an optical cable in the display unit, it is possible to perform information processing and input / output control. Furthermore, in the related art, a control I / O board, a connector used for data transmission between the input / output unit and the CPU, a connector, and a photocoupler used in the input circuit are omitted as a circuit configuration. This makes it possible to effectively utilize the space of the display light emitting element, and to achieve remarkable effects such as a reduction in PC mounting area and a reduction in parts cost.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an external appearance of a PC according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a block diagram showing a basic structure of the first embodiment of the present invention.

FIG. 4 is a connection diagram showing a second embodiment of the present invention.

FIG. 5 is a sectional view of a conventional PC.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light-emitting element for display 2 ... Body cover 3 ... Terminal block 4 ... Photocoupler 5 ... Connector 6 ... Output element 7 ... I / O plate 8 ... CP
U-plate 11 ... body cover 12 ... input display LED 13 ... output display LED 14 ... input LED cover 15 ... operation data input phototransistor 16 ... control data input phototransistor 17 ... light guide tube 18 ... I
/ O board 19 CPU board 20 Input circuit 21 Arithmetic circuit 22 Output circuit 25 Display unit 26 Optical cable

Continuation of front page (56) References JP-A-5-66813 (JP, A) JP-A-63-97910 (JP, A) JP-A-59-188703 (JP, A) JP-A-60-119194 (JP, A) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G05B 19/04-19/05

Claims (1)

(57) [Claims] A first input / output section comprising an input circuit for receiving an external signal and an output circuit for driving an external load;
A substrate, and a second substrate, which is provided so as to be insulated and separated from the first substrate by a light transmitting means, and includes a calculation control unit that performs a calculation process based on output information from the input / output unit. a pulp logs llama Bull controller Yusuke, said light transmitting means, the second phototransistor inputs information the input information and the first phototransistor for transmitting the operation control to the output from the first substrate and, LE for input / output
D, wherein the programmable controller is provided by the display unit.
A plurality of programmable controllers for performing an external display and via an optical cable connected to the display unit
A programmable controller characterized in that it enables interconnection of devices.