JPS6021648A - Optical signal generator - Google Patents

Abstract

PURPOSE:To improve the reliability by converting a start pulse and a short pulse in addition to a signal pulse including information to be transmitted into an optical signal and transmitting the result. CONSTITUTION:N sets of digital signal and M sets of analog signals converted (5) into digital signals are inputted to a shift register 4 as a processing signal. An oscillator 6 generates a signal A being a reference pulse and a short pulse signal B is generated from the signal A at a single shot multivibrator 3. A signal C frequency-dividing the signal A by 1/2 at a counter 1 is inputted to a clock terminal of the register 4 and a signal D frequency-dividing the signal A by 1/8 at a counter 2 is inputted to a reset terminal respectively, the processing signal is converted into a serial binary signal E and the result is outputted. A start pulse F is generated from an AND7 between the signals A and D, a pulse signal g is generated from an AND9 among the signals A, E and an inverting signal of the signal C, an output signal H of an OR10 among the signals F, B and G is converted into an optical signal and transmitted to a reception side 20. The signal B next to the signal F is detected for synchronism at the reception.

Description

[Detailed description of the invention] The present invention relates to an optical signal generator.

Normally, in order to transmit a large number of signals through a single transmission line, they are converted into serial signals using a shift register. In other words, transmitting data using a single transmission line is an essential technology from the standpoint of cost and reliability.
In particular, in order to input signals to a control unit such as a microcomputer,
This is an essential technology because it is not possible to read multiple signals at once.

In this case, if the transmitting side and the receiving side having a control unit are far apart and are controlled remotely using, for example, an optical fiber cable, the transmitting side and the receiving side must synchronize the signals and accurately transmit the signals. Therefore, the clock frequencies on the transmitting and receiving sides must be perfectly matched.

However, if the transmitting side is located outdoors and the clock is oscillated using a dry cell or battery as the power supply voltage,
This is because the clock frequency fluctuates easily and is also easily affected by noise due to external disturbances.

If the cycle between the transmitting side and the receiving side is different, there is a problem that the double signal is not transmitted or erroneous data is transmitted to the receiving side.

In view of this, the present invention generates a start pulse and a short pulse in addition to a signal pulse containing information to be transmitted on the transmitting side, and combines the signal pulse, start pulse, and short pulse with an 0++ circuit. .

An optical signal generating device that sequentially converts into optical signals.

It is an object of the present invention to provide an optical signal generating device with improved reliability, which is prevented from being erroneously read on the receiving side even if there is a fluctuation in the frequency of a reference pulse on the transmitting side as in the conventional case.

Hereinafter, five embodiments of the structure of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, the two examples of optical signal generators use a single shot 3 as an ordering means for generating short pulses, a shift register 4 as a conversion means, and a shift register 4 as a conversion means.
An example is given in which there are N digital signals and M analog signals as processing signals, and the analog signals are each converted into L-bit digital signals by the A/D B5 converter 5, and the The signal is input to the shift register 4. In addition.

The processed signal may be a signal corresponding to the degree of operation of the operating section or a signal indicating whether the operating section is connected or disconnected.

Next, the above N=2. M=1. When L=4, the first digital signal is Hl level and the second is LO level, and the states after converting the analog signal to 4 bits are HI and LO'.
, HL LO, (D case ni ('+7° will be explained.

The oscillator 6 oscillates a reference pulse (signal A), and from the signal A, the single shot 3 generates a short pulse (signal B) with a short pulse width that can be distinguished from the pulse width of the signal A at the rising edge. .

Furthermore, the signal A is frequency-divided by two (signal C) via the counter I, and is input to the clock terminal of the shift register 4. The signal C is frequency-divided by 8 by the counter 2 (signal 1
)) Input to the reset terminal of the shift register 4.

On the other hand, the shift register 4 converts the processed signal into a serial binary signal and outputs it (signal E).

A start pulse indicating the start of the binary signal is generated by signal A and signal R via an AND circuit 7 (signal F), and signal F is synchronized with the reference pulse and has the same pulse width as the reference pulse. has.

The signal G is a signal in which the signal E, the inverted signal of the signal C through the 2-inverter 8, and the signal A are outputted through the AND circuit 9, and corresponds to the "L" level of the signal E. Synchronized with signal A.

The signal 11 is a signal containing all the information to be transmitted, and is generated by combining the signal B (short pulse), the signal F (start pulse), and the signal G (signal pulse) through an OR circuit 1°. The signal H output in this way is transmitted to the amplifier 111.
The light is converted into an optical signal by the light emitting diode 12 and transmitted through one optical fiber cable 20.

On the other hand, as shown in Fig. 2, the signal H has a peak at the 2-bit start pulse. Among the signals, odd-numbered signals are always short pulses, and even-numbered signals are pulses with a value of %E. If the level is "1", it is a signal A pulse, and if it is a "0" level, it is a signal I3 (short pulse). Therefore, on the receiving side, after detecting the start bit indicating the start pulse, it is possible to take in the even-numbered signal and to confirm that the odd-numbered signal is a short pulse, thereby detecting an erroneous bisoto.

Next, in a case where the optical signal converted based on the large number of processed signals described above is applied to the control of an aerial work vehicle (not shown), the optical signal generating device is used as the transmitting side.

The central control device of the aerial work vehicle is assumed to be the receiving side, and the operation on the receiving side will be explained with reference to the block diagram shown in FIG. 3 and the flowchart shown in FIG. 4.

In FIG. 3, the central controllers 1 and 3 receive detection signals from the detection sections connected to each part of the above-mentioned aerial work vehicle, and the outrigger extension length 14. Poom J warehouse angle 15.
Boom angle 16. A signal from the boom load 17 operating section 18 is inputted via the analog/digital unit 19, while an optical signal from the workbench side transmitted by the optical fiber cable 20 and inputted via the optical demodulator 21 is transmitted to the beam ferrule. - It is input via the interface adapter 22, and serves as a signal for determining the safety limit of the work vehicle together with the detection signal.

Further, the amplifier 24 is assembled into a control signal from the peripheral interface adapter 22 to control one of the control units, for example, a solenoid valve 23 for boom-related operation.
Output via . In the figure, 25 is a CPU, 26 is a memory, and 27 is a defective lamp, which is turned on when an error is discovered in the optical signal.

In FIG. 4, steps (2) to (2) are steps for detecting a start bit, and in step (2), the data of the label name BFSH is cleared.

The BFSW stores information before the optical signal read in step (2). The optical signal read in step ■ continues to be read in step ■ until a rising edge signal is confirmed in step ■.

If a rising edge is detected in step (2), the process will wait for one hour in step (2). This one hour is set between the times corresponding to one pulse width of the signals A and B. Next, read the relevant pulse again in step ■, and “
If it is at the "1" level, it is determined that it is a pulse of signal A, and if it is at "0" level in step (2), it can be determined that it is a pulse of signal B.

If it is a pulse of signal B, at least it does not indicate a start bit, so in step
Clear and return to step ■. On the other hand, if it is a pulse of signal A, the BFSW stored in step
Determine whether the content of is at the “1” level.

If the level is not "1", the contents of the BFSW are set to "1" level in step (2) and the process returns to step (2). Step ■
If it is determined that the contents of the BI'SW stored in advance are at the "1" level, that is, the start pulse is confirmed to be a signal A pulse followed by "2 bits". In steps [phase] to (2), the start bit is removed (even-numbered signals of the optical signal are stored as switch information).

When an odd-numbered pulse of signal A is detected, steps are shown until the abnormality lamp 27 is turned on, and step 7
The counter is cleared in step [phase], the optical signal is read in step (2), and it is determined W1 whether the optical signal is rising in step @, and the reading in step (2) is continued until the rising edge is detected. When the rising edge of the optical signal is detected in step [phase], the content of the counter is incremented in step 0.

In step ■, the value of the counter and (Nx2+MxLx2)
is compared with the value of When the value of the counter is larger than that value, it means that all the switch information has been read, so return to step (3).

When the counter value is small, move to step [phase]. Steps [phase] to O are performed in the same manner as steps ① to ② above.

It is determined whether the optical signal is a pulse to signal or a pulse to signal B. If it is determined that it is a pulse to the signal, and the counter value is an odd number in step [phase], and the counter value is an even number in step [phase], the information is stored in step (2).

However, if the count value is an odd number in step [phase], the abnormality lamp 27 is turned on in step @. on the other hand,
If the optical signal is not at the “1” level in step O, step [
Transfer to phase]. Further, if the count value is not an even number in the Stesov cycle, the information is not stored and the process returns to step 0 in the same way as step (2).

The switch information stored as described above is as follows.

It is updated as appropriate so that new information is always stored, and the boom-related operating electromagnetic valve 23 is controlled based on this information.

The present invention generates a start pulse and a short pulse in addition to a signal pulse containing information to be transmitted on the transmitting side, and combines the signal pulse, start pulse, and short pulse with an OR circuit to sequentially convert the signal pulse into an optical signal. Because the signal pulse is converted, the start of the signal pulse can be easily confirmed by detecting the start pulse, and synchronization on the receiving side can be easily achieved.Even if the frequency of the reference pulse on the transmitting side varies, the short pulse Since the pulse width is short enough to be distinguishable from the reference pulse, there is no possibility of erroneous reading on the receiving side, resulting in an optical signal generating device with extremely improved reliability.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the overall configuration of the optical signal generator of the present invention, Fig. 2 is a timing diagram explaining the operation of Fig. 1, and Fig. 3 is a block diagram showing the central control unit on the receiving side. , FIG. 4 is a flowchart illustrating the operation on the receiving side. 3...Single shot 4-...Shift register 5
... A/D converter, 6... Oscillator 10...01
Circuit, 13...Central control unit 19...Analog.
Digital unit 20... Optical fiber cable 22... Peripheral interface adapter 23... Solenoid valve, 25... CPU 27...
abnormal lamp

Claims (1)

[Scope of Claims] 1) An oscillator that oscillates a reference pulse, a pulse generating means that synchronizes with the rising edge of the reference pulse and has a short pulse width distinguishable from the reference pulse, and a processed signal that oscillates the reference pulse. It includes a conversion means for converting the pulse into a serial binary signal synchronized with the pulse, and a start pulse generating means for generating a start pulse indicating the start of the serial binary signal, and a reference pulse and a reference pulse corresponding to the binary signal. An optical signal generator characterized in that it generates synchronized signal pulses, combines the Shingetsu pulse, short pulse and start pulse with an OR circuit, and sequentially converts them into optical signals. 2) The optical signal according to claim 1, wherein the optical signal is guided to a central control unit via one optical fiber cable and assembled into a signal for controlling and controlling the corresponding control unit. Signal generator. 3) The optical signal generating device according to claim 1, wherein the processed signal is a plurality of digital signals corresponding to connection/disconnection of the operating section. 4) The optical signal generating device according to claim 1, wherein the processed signal is a plurality of analog signals corresponding to the degree of operation of the operating section. 5) The optical signal generating device according to claim 4, wherein the plurality of analog signals are input to the converting means after being converted into digital signals via an A/D converter.