JP3099487B2 - Non-line / optical communication equipment for transmission terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the field of FA and the like. The present invention relates to an optical communication device of a transmission terminal that performs optical communication with the outside without passing through a transmission line.

[0002] In the drawings, the same reference numerals indicate the same or corresponding parts.

[0003]

2. Description of the Related Art FIG. 4 shows an example of the configuration of a general multi-drop connection line transmission system. In FIG. 1, reference numeral 8 denotes a transmission line, 10 denotes a transmission terminal connected to the transmission line 8 in a multi-drop manner, and 21 denotes a transmission center for controlling transmission of the system. 22 (22-1, 22-2,
..) Are input / output means for the transmission terminal 10.
1 is an indicator light, 22-2 is a switch.

[0005] FIG. 5 is a block diagram showing an example of a conventional address setting method for the transmission terminal 10. In FIG. 1, reference numeral 5 denotes a control circuit which is a main control unit in the transmission terminal 10 and comprises a microprocessor or the like. 6 and 7 are transmission lines 8 respectively
And a driver 22-3 serving as an interface for receiving and transmitting the transmission of the control circuit 5 to the control circuit 5, and a DIP switch 22-3 for setting an address as input means 22 to the control circuit 5.

FIG. 6 is a block diagram showing another example of the conventional address setting system. FIG. 6A shows the configuration of a transmission terminal, and FIG. 6B shows the configuration of a transmission system at the time of address setting. Show. Here, 24 is the EEPRO loaded on the control circuit 5.
M (that is, an electrically erasable PROM), and 9 in FIG. 3B, an address setting device provided on the transmission line 8 instead of the transmission center 21.

That is, in FIG. 6, an EEPROM 24 is provided inside the transmission terminal 10 as shown in FIG. 1A, and address setting communication is added to one of the transmission functions, and as shown in FIG. 21 or setting device 9 and transmission terminal 1: 1
The address is set in the EEPROM 24 through the control circuit 5 of the transmission terminal 10 so that the address of the transmission terminal 10 does not overlap with other transmission terminals in the transmission system. This is because if the transmission center 21 or the setting device 9 and a plurality of transmission terminals 10 are installed and setting communication is performed, a plurality of transmission terminals 10 are set to the same address due to multidrop, so that a transmission system cannot be configured. It is.

[0007]

However, as shown in FIG. 5, the address of the transmission terminal 10 is assigned to the DIP switch 22-3.
In the method of setting, the terminal 10 may be enlarged due to the outer shape of the DIP switch 22-3, and an erroneous address may be set due to poor contact of the switch 22-3.

In the method of adding an address setting communication function to the transmission function as shown in FIG. 6 and connecting the transmission center 11 or the setting unit 9 to the transmission terminal 10 in a one-to-one manner, the transmission terminal 10 is laid. The work of setting the address after the construction is completed, the work of confirming the address that occurs because the address of each terminal cannot be seen, or the change of the address are cumbersome and difficult.

In the case of FIG. 6, if a serial transmission function for setting an address is added to the transmission terminal 10 by temporary contact of an electric wire, the external shape of the transmission terminal 10 becomes larger due to the addition of a connector, or the connector portion is dustproof. Need measures,
Alternatively, since an electric wire for serial transmission for address setting is wired even temporarily, there arises a problem that a surge countermeasure is required inside the transmission terminal.

Accordingly, an object of the present invention is to easily set, check, and change the address after the transmission terminal 10 is laid, and to set, check, and change the address without electrical connection to the transmission terminal 10. An object of the present invention is to provide a non-line / optical communication device for a transmission terminal.

[0011]

In order to solve the above-mentioned problems, a non-line / optical communication apparatus according to a first aspect of the present invention includes a transmission line (8).
LED for operation display
In a transmission terminal (e.g., 10) provided with (e.g., 1), a means for illuminating the LED in pulses for the operation display (e.g., transistors Tr1, Tr3, and a control circuit 5); Means for receiving a signal.

Further, in the non-line / optical communication apparatus according to claim 2,
2. The optical communication device according to claim 1, wherein the transmission terminal is provided with a means (such as a setting unit 9) for providing a serial transmission signal by emitting light (such as the LED 11) to the LED. Further, in the non-line / optical communication apparatus according to claim 3, in the optical communication apparatus according to claim 1 or 2, the light receiving signal receiving means of the LED is provided by the LE.
Means for biasing D to 0 or reverse bias (transistor Tr2 etc.), means for detecting the current flowing to the LED at the time of 0 bias or reverse bias (op amp 3 etc.), and decoding the detection signal of this current detecting means Means (comparator 4, control circuit 5, etc.).

[0013]

The operation display LED provided in the transmission terminal is pulse-lit by a transistor, and the LED is used as a light receiving element during the light-out period of the LED. While the LED operates as a light receiving element, the light receiving signal of the LED is input to the control circuit via the operational amplifier and the comparator. LED
The lighting time of can be changed by a transistor.

Further, a setting device having the same circuit configuration for controlling the transmission terminal and the LED and having a man-machine interface through which an operator can input an address is prepared separately from the transmission terminal. In this way, the transmission terminal is pulse-lit L
Since the LED functions as a light receiving element during the light-off period of the ED, the LED signal emitted from the setting device can be detected. By this detection, the control circuit of the transmission terminal switches its operation mode from the display operation mode of the LED to the address setting, confirmation, and change mode, and transmits an optical transmission signal by turning on / off the LED of the external setting device to the LED of the transmission terminal. To set, confirm, and change the address.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of a main part of a transmission terminal 10 and a setting unit 9 as an embodiment of the present invention. In this transmission terminal 10, 1 is L which serves both as a display element and a light receiving element.
ED, Tr1, Tr2, Tr3 are transistors for driving the LED1, 3 is an operational amplifier for detecting the light receiving current of the LED1, and 4 is the output voltage of the operational amplifier 3 as a reference voltage r.
ef.

TX / (RX) is a transmission / reception (mode) switching signal output terminal of the control circuit 5, RXD is a reception data input terminal of the control circuit 5, and TXD is a transmission data output terminal of the control circuit 5 as well. is there. In FIG. 1, the same LED as the transmission terminal 10, its driving circuit, and a light-receiving signal detection circuit are also provided in the setting unit 9 outside the transmission terminal 10, and 11 is an LE corresponding to 1 of the transmission terminal 10.
D and Tr11 to Tr13 denote transistors corresponding to Tr1 to Tr3, respectively, 13 denotes an operational amplifier corresponding to 3, and 14 denotes a comparator corresponding to 4. Reference numeral 15 denotes a microprocessor corresponding to the control circuit 5 of the transmission terminal 10;
X / (RX) 1 is a transmission / reception mode switching signal output terminal corresponding to the terminal TX / (RX) of the transmission terminal 10;
XD1 is a reception data input terminal also corresponding to the terminal RXD, and TXD1 is a transmission data output terminal also corresponding to the terminal TXD.

FIG. 2 is a block diagram showing a modified embodiment of FIG. 2, the LE of the transmission terminal 10 is different from that of FIG.
The drive circuit and connection polarity of the drive transistors Tr1 to Tr3 with respect to D1 and the connection polarity of the photocurrent detection circuit are different. However, in FIG.
1 is set to 0 bias state, whereas in FIG.
2 is the same as that of FIG. 1 except that the operation is reverse biased.

FIG. 3 is a time chart for explaining the operation of FIGS. 1 and 2, in which, from the top, the blinking timing of the LED 1 of the transmission terminal 10, the operation timing of the LED 11 of the setting unit 9, and the reception data of the transmission terminal 10. The timing of signal input to the input terminal RXD is shown. Next, the operation of FIGS. 1 and 2 will be described with reference to FIG. The LED 1 for displaying the operation of the transmission terminal 10 is always pulse-lit at, for example, a frequency of 500 Hz as in the period T1 in FIG. 3, but the blinking speed of the human eye is so high that the blinking of the LED cannot be recognized. In FIG. 1 and FIG. 2, the path of the lighting current of LED1 is from power supply → transistor Tr1 → LED1 → transistor Tr3 → ground GND. To turn on Tr1 and Tr3, the output signals of terminals TX / (RX) and TXD are set to 'H'. '.

On the other hand, during the extinguishing period of the LED 1 which is operatively displayed by the pulse lighting, the transistor Tr1 is turned off and Tr1 is turned off.
The LED1 and the operational amplifier 3 constitute an IV conversion circuit that converts a light receiving signal of the LED1, that is, a current signal into a voltage by turning the transistor 2 on and the transistor Tr3 off. Originally, when the LED1, which is a light emitting element, is in a 0V bias state as shown in FIG. 1 or a reverse bias state as shown in FIG. 2, an empty layer is formed at the junction, and when light is irradiated, a current flows from the cathode to the anode similarly to the photodiode. Is performed.

At this time, the path of the light-receiving current of LED1 is shown in FIG. 1 as the output terminal of operational amplifier 3 → resistance R1 → LED1 →
The transistor Tr2 becomes the ground GND. In FIG. 2, the power supply becomes the transistor Tr2, the LED1, the resistor R1, and the output terminal of the operational amplifier 3. Thus, the light-off period t in FIG.
2 is irradiated with light of the LED 11 from the setter 9 side, a current flows through the feedback resistor R1 of the operational amplifier 3 in FIGS. 1 and 2, and a light receiving signal from the setter 9 is applied to the output of the operational amplifier 3 as a voltage. Is obtained as Further, by comparing this voltage signal with the comparison reference voltage ref by the comparator 4, a digital reception signal is obtained, and the control circuit 5 inputs this reception signal to the reception data input terminal RXD and decodes it.

Here, the reference voltage ref as the threshold value of the comparator 4 is set to a level at which the sunlight and fluorescent light emitted from the surroundings are not determined as a light receiving signal. On the other hand, during the light emission of LED1 (period t1 in FIG. 3), LED1
With the flow of a large current compared to the current that is received and transmitted, a large amount of excessive minority charges are accumulated in the base region (n side) of the base region. Since the LED 1 has no light receiving ability until the period t3 in FIG. 3 elapses, the light receiving determination of the reception data input terminal RXD of the control circuit 5 is performed immediately before the operation display of the LED 1 as shown in FIG. Is turned off and about 1 msec elapses.

Thereafter, the transmission terminal 10 detects the lighting state transmitted from the setting unit 9 for 5 msec or more, and then detects the lighting state.
After receiving the transmission data of the address setting transmitted during the period T2 in FIG. 3 and judging the error, if there is no error, the address set by the setting unit 9 is changed to 1 msec.
In a later period T3 of FIG.
Is transmitted as response data. Upon receiving this response data, the setting unit 9 further sets the period T4 of FIG. 3 after 1 msec.
Then, by transmitting an ACK signal to the transmission terminal 10, the setting communication is terminated.

The transmission terminal 10 receiving this ACK signal
Writes an address newly set by communication with the setting unit 9 in the EEPROM 24 and holds the address.
If there is an error in the transmission procedure, the transmission terminal 10 turns the LED 1 on in a pulse (operation display state) and resets the settings from the beginning. In addition, the setting unit 9 does not proceed to the transmission procedure up to the transmission of the ACK. If the transmission stops halfway, an error is displayed on a display unit (not shown) of the setting unit 9, whereby the setter performs resetting.

For transmission using the LEDs 1 and 11, the setting unit 9 emits a transmission command for reading the address from which the transmission terminal 10 emits light, so that the transmission terminal 1 emits light.
It is also possible for the setting unit 9 to confirm the address of 0.

[0025]

According to the present invention, the LED for displaying the operation of the transmission terminal is used as a light receiving means for serial transmission for address setting (by optical communication) without using the transmission line of the transmission terminal. Even after laying the address, setting, checking, and updating of the address can be easily performed without electrical connection between the setting device and the transmission terminal.

The present invention also relates to a transistor, an operational amplifier,
If a simple circuit of the comparator is used and the control circuit of the transmission terminal is a microcomputer, it can be realized by a simple change of software. Further, the present invention provides an L for operation display.
Since the ED is used as the light receiving means for serial transmission of the address setting, the appearance of the product does not change at all.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration as an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a modified example of FIG. 1;

FIG. 3 is a time chart showing transmission timing using the LEDs of FIGS. 1 and 2;

FIG. 4 is a configuration diagram of a general multi-drop line transmission system.

FIG. 5 is a configuration diagram showing an example of a conventional transmission terminal address setting method.

FIG. 6 is a configuration diagram showing another example of a conventional transmission terminal address setting method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 LED Tr1 transistor Tr2 transistor Tr3 transistor 3 operational amplifier 4 comparator 5 control circuit 6 receiver 7 driver 8 transmission line 9 setting device 10 transmission terminal 11 LED Tr11 transistor Tr12 transistor Tr13 transistor 13 operational amplifier 14 comparator 15 microprocessor 21 transmission center 24 EEPROM

Claims (3)

(57) [Claims] 1. A transmission terminal multi-drop-connected to a transmission line and provided with an LED for operation display, means for pulsing the LED for the operation display, and a light receiving signal of the LED when the LED is turned off. And a means for receiving a communication line. 2. An optical communication apparatus according to claim 1, wherein said transmission terminal is provided with means for externally providing a serial transmission signal by light emission to said LED. Optical communication device. 3. The optical communication device according to claim 1, wherein said LED light receiving signal receiving means comprises an LE.
Means for biasing or reverse-biasing D;
A non-line / optical communication apparatus for a transmission terminal, comprising: means for detecting a current flowing through the communication terminal; and means for decoding a detection signal of the current detection means.