JP3301229B2 - Serial signal transmission device and serial signal transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial signal transmission apparatus for transmitting and receiving serial signals and a serial signal transmission method, and more particularly to a serial signal transmission apparatus capable of simultaneously supplying power together with data transmission when transmitting and receiving data. And a serial signal transmission method.

[0002]

2. Description of the Related Art Conventionally, in signal transmission between devices,
There are parallel transmission that can transmit a large amount of data in order to transmit and receive data in parallel at one time, and serial transmission that transmits and receives data one by one in series. The most different point on the hardware constituting the apparatus due to the difference between these transmission systems is a great difference in the number of cables connecting the transmitting and receiving apparatuses. In addition, when only data communication is considered, parallel transmission that can transmit data at one time is more advantageous.

[0003] However, it is more advantageous to adopt serial transmission as the cable for connecting the transmitting and receiving devices in consideration of the cable installation work and the space problem when installing the cable. In other words, as for the number of cables connected between the devices, the less the number, the labor for laying the cables is reduced, and the space for installing the cables has a margin, so that the cables for other devices can be laid out. is there.

[0004] Therefore, in recent years, the speed of communication semiconductor elements has been increased, and optical communication using an optical fiber or the like has been carried out. As a result, serial transmission has been widely used.

FIG. 10 shows a conventional serial signal transmission device for performing serial transmission.

This device includes a serial signal transmitting device 1 for transmitting a parallel signal of input data as a serial signal, and a serial signal receiving device 5 for receiving a serial signal from the serial signal transmitting device 1 and converting it into a parallel signal again. There is. A serial signal cable 9 for transmitting a serial signal and a power cable 10 for supplying power from the serial signal transmitting device 1 to the serial signal receiving device 5 are provided between the devices. The serial signal transmitting device 1 includes a parallel signal input unit 2 for interfacing a parallel signal input from the outside and converting the signal into a serial signal, and a serial signal transmitting unit 3 for controlling a data signal when transmitting the serial signal. And a power supply unit 4 for supplying power from an external power supply to the serial signal receiving device 5. The serial signal receiving device 5 includes a serial signal receiving unit 6 that receives a serial signal from the serial signal transmitting device 1 and controls a data signal, and a power demand unit 8 that receives power from the serial signal transmitting device 1. There is a parallel signal output unit 7 for converting a received serial signal into a parallel signal again and outputting it to the outside.

This device operates as follows.

A parallel signal of data input from the outside is converted from a parallel signal into a serial signal by a parallel signal input unit 2 and input to a serial signal transmitting unit 3. When the serial signal input to the serial signal transmission unit 3 is transmitted to the serial signal receiving device 5 by the serial signal transmission unit 3, control such as start and end of transmission is performed. The serial signal transmitted through the serial signal cable 9 in this manner is received by the serial signal receiving unit 6 and is controlled by the serial signal transmitting apparatus 1 according to the internal processing status. I do. The serial signal received by the serial signal receiving unit 6 is converted from a serial signal into a parallel signal again by the parallel signal output unit 7 and output to the outside.
On the other hand, after power from the outside is supplied to the serial signal transmitting device 1, the power is supplied to the power demanding portion 8 through the power cable 10 by the power supply portion 4 to operate the serial signal receiving device 5.

However, the provision of the serial signal cable and the power cable for transmitting the serial signal and supplying the electric power as described above is advantageous in performing the serial transmission, such as saving the labor of arranging the cable and other factors. This has hindered the increase in space for installing cables between devices, and as a result, labor for laying cables could not be saved much, and the space for arranging cables for other devices was not secured. .

In order to solve such a problem, Japanese Patent Laid-Open No.
As disclosed in US Pat. No. 244,174, a device for supplying power simultaneously with transmission of a serial signal is disclosed.

This device uses +24 V as a data serial signal and uses −24 V as a power signal to be supplied to a receiving device. Therefore, the above-described device eliminates the need for a power cable, and can use only a serial signal cable, thereby reducing the above-described problems.

However, in this device, +2
A power supply circuit of a different voltage of ± 24 V is required because a power supply of 4 V and −24 V is required, or M is required because a data signal of +24 V is used.
When a data signal is processed by a PU (microprocessor unit), the voltage must be reduced to +5 V or +3 V, and therefore a step-down circuit is required. Therefore, this device has a complicated circuit configuration, increases the number of assembling steps of the device, and lowers the maintainability of the device.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to simplify the circuit configuration, which is a problem, to reduce the assembly process of the device, to improve the maintainability of the device, and to arrange the cables. An object of the present invention is to provide a serial signal transmission device and a serial signal transmission method capable of performing serial signal transmission and power supply using the same cable in order to save labor and increase the space for installing cables between other devices. Aim.

[0014]

The present invention for solving the above-mentioned object is based on the following means.

1. A serial signal transmission device according to the present invention includes a serial signal transmission device that receives a parallel signal, converts the parallel signal into a serial signal, and transmits the serial signal, and a serial signal reception device that converts a serial signal from the serial signal device into a parallel signal Wherein the serial signal transmitting device includes a serial signal converting means for converting a parallel signal as a data signal into a data signal as a serial signal; and Signal generating means for generating a power signal to be supplied to a signal receiving device; signal modulating means for modulating the data signal and the power signal from the serial signal converting means; and the data modulated by the signal modulating means. Signal for increasing the power capacity of the signal and the modulation signal of the power signal. And a capacity increase means,
Wherein the serial signal receiving device includes: a power demodulator for demodulating the modulated signal into the power signal to obtain power; and a serial signal detecting means for detecting the modulated signal without being affected by the power demodulator. And, a serial signal demodulating means for demodulating the modulated signal from the serial signal detecting means to a data signal from the serial signal transmitting device,
And a parallel signal conversion means for converting the data signal from the serial signal demodulation means into a parallel signal.

[0016]

[0017]

2 . The serial signal transmission method of the present invention converts a parallel signal that is a data signal into a data signal that is a serial signal, and supplies power to the outside together with the converted data signal and the data signal that changes at a constant cycle. The power signal is modulated by performing an exclusive OR operation, the power capacity of the modulated signal is increased, the modulated signal having the increased power capacity is transmitted to the outside, the received modulated signal is demodulated, and the power and the data are received. A signal is obtained, and the obtained data signal is converted into parallel data.

[0019]

[Action]

1. The serial signal transmission device of the present invention converts a parallel signal input from the outside into a data signal which is a serial signal by a serial signal conversion means in the serial signal transmission device. The converted data signal and the power signal of a fixed period generated by the signal generating means for supplying power to the serial signal receiving apparatus are modulated by performing an exclusive OR operation by the signal converting means, and the serial signal is modulated. Signal. This modulated signal is transmitted to the serial signal receiving device after the power capacity is increased by the power capacity increasing means. The modulated signal transmitted to the serial signal receiving device is smoothed by power demodulation means in the serial signal receiving device to become power supplied to the serial signal receiving device. On the other hand, the modulated signal is detected by the serial signal detecting means without being affected by the power demodulating means. The detected modulated signal is a data signal only after the power signal is removed by the serial signal demodulating means,
The signal is converted into a parallel signal again by the parallel conversion means and output to the outside.

[0020]

2 . The serial signal transmission method of the present invention converts a parallel signal into a data signal that is a serial signal. The converted data signal and a power signal having a predetermined period for supplying power to the outside together with the converted data signal are subjected to an exclusive OR operation to modulate the data signal into a modulated signal as a serial signal. This modulated signal is transmitted to the outside with its power capacity increased. The received modulated signal is smoothed to provide power to the receiving device. on the other hand,
The modulated signal is removed from the power signal without being affected by the smoothing, becomes a data signal only, and is converted into a parallel signal again. Therefore, the method can simultaneously supply a serial signal and power in transmission between devices.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A serial signal transmission device and a serial signal transmission method according to the present invention will be described below with reference to the accompanying drawings.

This device includes a serial signal transmitting device 1 and a serial signal receiving device 5 as shown in FIG.

The serial signal transmitting apparatus 1 includes a parallel signal input section 2 and a serial signal transmitting / transmitting section for modulating a data signal and power as serial signals from the parallel signal input section 2 and transmitting the modulated signal and the power to the serial signal receiving apparatus. 11
There is. On the other hand, the serial signal receiving device 5 includes a parallel signal output unit 7, a serial signal receiving and transmitting unit 12 for demodulating a serial signal from the serial signal transmitting device 1 to obtain a data signal and power, and a serial signal cable 9.

Further, the parallel signal input section 2 includes a protection circuit section 21 for protecting other circuits from overvoltage or the like when the parallel signal contains an abnormal voltage and applied from outside, and a parallel signal from the protection circuit section 21. There is a serial conversion unit 22 that is a serial signal conversion unit that converts a data signal that is a serial signal. The serial signal transmission / transmission unit 11 includes a clock generation unit 32 that is a signal generation unit that generates a square wave having a constant period as a power signal, and a data signal and a clock generation unit 32 from the serial conversion unit 22.
A signal modulating unit 31 that is a signal modulating unit that performs an exclusive OR operation on the power signal from the unit and modulates the power signal; an amplifying unit 33 that is a power capacity increasing unit that increases the power capacity of the modulated signal from the signal modulating unit 31; Serial signal receiving device 5 for modulated signal
There is a transmission control unit 34 for adding communication data such as a start bit as a communication start signal when transmitting a serial signal to perform communication control.

Further, the serial signal receiving and transmitting section 12
Are a smoothing circuit section 41 which is a power demodulating section for obtaining a power by smoothing the modulated signal from the serial signal transmitting apparatus 1 and a serial signal detecting section for detecting the modulated signal without being affected by the smoothing circuit section 41. A serial signal detection unit 42, a filter unit 43 for reducing noise components of the modulated signal produced by the serial signal detection unit 42, and a serial signal demodulation in which the power signal is removed from the modulated signal from the filter unit 43 and only the data signal is output. There are a signal demodulation unit 44 as a means, and an error detection unit 45 for detecting whether the demodulated data signal is in a set serial signal format. The parallel signal output unit 7 converts the data signal demodulated by the signal demodulation unit 44 into a parallel signal again. The parallel signal conversion unit 51 converts the data signal into a parallel signal. There are an output control unit 52 for adding communication data such as an end bit at the end of the communication and performing communication control, and an amplification unit 53 for increasing the power capacity of the parallel signal.

The amplifiers 33 and 53 are servo amplifiers or the like, and increase only the power capacity without dulling the signal waveform. As the filter unit 43, an appropriate filter such as an LC filter and an active filter may be used as long as it can remove the noise component of the modulated signal.

The above-described apparatus operates as follows.

In the serial signal transmitting device 1, even if an abnormal voltage or the like is input to the serial signal transmitting device 1, the parallel signal input from the outside is subjected to overvoltage protection and the like by the protection circuit section 21 and other circuits are provided. Malfunctions are prevented. The parallel signal that has passed through the protection circuit unit 21 is converted into a serial signal by the serial conversion unit 22 in synchronization with a square wave generated by the clock generation unit 32.
The data signal converted into the serial signal is modulated by the signal modulation unit 31 with a power signal that is a square wave generated by the clock generation unit 32. The modulated signal is a modulated signal obtained by performing an exclusive OR operation on the data signal and the power signal as in the Manchester modulation shown in FIG. 4, for example. The power of the modulated signal is increased by the amplifying unit 33, controlled by the transmission control unit 34 in synchronization with the square wave generated by the clock generating unit 32, and transmitted to the serial signal receiving device 5.

The transmitted modulated signal is smoothed by the smoothing circuit section 41 in the serial signal receiving device 5 and supplied as power to the serial signal receiving device 5. On the other hand, the modulated signal is sent to the smoothing circuit unit 4 by the serial signal detection unit 42.
The modulation signal is detected without being affected by 1. The modulated signal detected by the serial signal detection unit 42 is filtered by the signal demodulation unit 44 after the noise component is removed by the filter unit 43.
The power signal is removed, leaving only the data signal. This data signal is detected by the error detection unit 45 as to whether or not it is in a serial signal format, and if there is an abnormality, an error signal is output. The data signal is converted into a parallel signal by the parallel conversion unit 51, and communication control such as start or end of signal output is performed by the output control unit. The parallel signal obtained in this way is
After the power capacity is further increased by the amplifier 53, the power is transmitted to another facility.

FIG. 5 is a flowchart of the control of the present apparatus.

The parallel signal is converted into a data signal which is a serial signal (S1), and the data signal and the power signal which changes at a constant period are subjected to exclusive OR to be modulated (S1).
2). By increasing the power capacity of the modulated signal (S
3) Transmit the modulated signal (S4). The received modulated signal is demodulated to be a data signal, and the modulated signal is smoothed and used as the power of the receiving device (S5). Then, the data signal is converted into a parallel signal again (S6).

The above-described serial signal detection section 42 and smoothing circuit section 41 are constituted and operated by the following circuits, for example.

FIG. 6 shows that the primary side and the secondary side are connected by the transformer TR1.
The secondary side is insulated so as not to be affected by the smoothing circuit unit 41 for smoothing the modulation signal, and the smoothing circuit unit 41 is
It is a converter. In the case of this DC-DC converter, in the case of this device, the primary side of the transformer is switched by a switching element with a single power supply to charge or discharge the inductance of the transformer, thereby generating an alternating current inside the transformer. The rectifier is used on the secondary side of the transformer to convert it again to a single power supply, that is, a DC power supply. The serial signal detector 42 is a comparator CMP connected to the primary side of the transformer TR1 and can detect a modulation signal from the primary side of the transformer TR1 without being affected by the smoothing circuit section 41. Further, the smoothing circuit section 42 uses the transformer TR1 to increase or decrease the voltage of the transformer TR1 or 1 according to the transformation ratio of the transformer TR1.
The modulation signal output directly from the voltage applied to the next side is half-wave rectified by the diode D1. The partially rectified voltage is smoothed by a capacitor C1, and a high frequency component is removed by a filter including a resistor R1 and a capacitor C2. Further, the resistor R1 limits the power supplied to other circuits in order to prevent the modulation signal from being undetectable on the primary side when a large amount of power on the secondary side of the transformer is used.

FIG. 7 shows a DC-DC converter in which the smoothing circuit section 41 has the same configuration as the smoothing circuit section 41 shown in FIG. This is a circuit in which the modulation signal on the primary side of the transformer TR1 is insulated and separated by a photocoupler PC1 into a power supply line and a signal line so as not to be affected by load fluctuation noise flowing through the power supply line. Serial signal detector 42
, The switching operation is improved by resistors R1 to R3 connected to the photocoupler PC1, the rounding of the modulation signal is reduced, and the current flowing through the photocoupler PC1 is limited to protect the photocoupler PC1. Further, the smoothing circuit unit 41 operates in the same manner as the smoothing circuit unit 41 of FIG. 6 with the same configuration.

FIG. 8 shows a circuit in which the smoothing circuit section 41 is composed of a series regulator, and a serial signal detecting section 42 is provided with a photocoupler so that a modulation signal can be detected without being affected by the smoothing circuit section 41. It is. The serial signal detector 42 has the same configuration as the serial signal detector 42 of FIG. 7 and operates similarly. The smoothing circuit section 41 is a series regulator in which the voltage stepped down by the transistor Q1 is determined by the Zener diode ZD1 and the current flowing into the transistor Q1 is limited by the resistor R5. The resistor R1 and the capacitors C1 and C2 are shown in FIG. 6
The same operation as is performed.

FIG. 9 shows a smoothing circuit unit 4 using a photocoupler.
1 is a circuit that can detect a modulation signal without being affected by the signal of the first embodiment. The serial signal detector 42 is provided with a photocoupler P
The photocoupler PC1 is connected by the resistor R1 connected to C1.
The current flowing through the light-emitting diode built in is limited and protected. Further, the smoothing circuit unit 41 operates in the same manner as the smoothing circuit unit 41 of FIG. 6 with the same configuration.

The present apparatus configured and operated as described above performs an exclusive OR operation of the data signal and the power signal which is a square wave, and is constituted by a smoothing circuit section even when the data signal is not output. The DC-DC converter can be operated to supply power to the serial signal receiving device.
By using a transformer for the waveform smoothing circuit, etc.
A DC-DC converter can be configured to supply power to a serial signal receiving device together with a data signal from a serial signal transmitting device using only a single power supply. Further, in this case, since the desired voltage can be obtained only by adjusting the transformer transformation ratio, the power supply voltage can be easily changed according to the use of the serial signal receiving device. If the voltage supplied to the serial signal receiver is intended only to reduce the voltage, the desired voltage can be easily obtained with a simple circuit configuration by using a series regulator or the like for the smoothing circuit section, and the data signal can be obtained. Power can be obtained. When the voltage level of the signal transmitted from the serial signal transmitting device is equal to the voltage level of the signal processed by the serial signal receiving device, the data signal and the power are received by a simpler circuit using a photocoupler. Can be transmitted to the device.

[0039]

As described above, the apparatus according to the present invention has the following effects.

1. The serial signal transmission device of the present invention performs an exclusive OR operation on a power signal of a fixed period generated by a signal generation unit and a data signal which is a data signal to be transmitted in a serial signal transmission device. Since power and data signals are transmitted to the signal receiving device, power can be transmitted even when no data signal is input. On the other hand, this device
In the serial signal receiving device, the power and data signals can be transmitted with a single power supply by a DC-DC converter or the like constituted by the power demodulating means, the serial signal detecting means, and the serial signal demodulating means. Can be set to a desired voltage. Therefore, the present apparatus simplifies the circuit configuration, reduces the number of assembling steps of the apparatus, improves the maintainability of the apparatus, and further saves labor for arranging cables and installs a space between other apparatuses. Can be increased.

[0041]

[0042]

2 . Since the serial signal transmission method of the present invention performs an exclusive OR operation on the data signal and a power signal of a fixed period for supplying power to the outside together with the data signal and transmits the signal to the receiving side, for example, the data signal is not input. But it can transmit power. Further, according to the present method, a transmitted signal can be smoothed to obtain power and demodulated into a data signal without being affected by the smoothing, so that serial signals and power can be simultaneously supplied in transmission between devices. Become.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a serial signal transmission device according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a serial signal transmission device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a serial signal receiving device according to the present invention.

FIG. 4 is a drawing for explaining Manchester modulation by the serial signal transmission device of the present invention.

FIG. 5 is a flowchart for explaining control of the serial signal transmission device of the present invention.

FIG. 6 is a diagram for explaining a configuration of an embodiment of a serial signal detection unit and a power demodulation unit of the serial signal transmission device of the present invention.

FIG. 7 is a diagram for explaining a configuration of an embodiment of a serial signal detection unit and a power demodulation unit of the serial signal transmission device of the present invention.

FIG. 8 is a diagram for explaining a configuration of an embodiment of a serial signal detecting unit and a power demodulating unit of the serial signal transmission device of the present invention.

FIG. 9 is a drawing for explaining a configuration of an embodiment of a serial signal detecting means and a power demodulating means of the serial signal transmission device of the present invention.

FIG. 10 is a diagram illustrating a configuration of a conventional serial signal transmission device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Serial signal transmission device, 2 ... Parallel signal input part, 3 ... Serial signal transmission part,
4: power supply unit, 5: serial signal receiving device,
6: Serial signal receiving unit, 7: Parallel signal output unit, 8: Power demand unit, 9
... Serial signal cable, 10 ... Power cable, 11 ... Serial signal transmission / transmission unit,
21: protection circuit section, 22: serial conversion section,
31 ... signal conversion unit, 32 ... clock generation unit, 33, 53 ... amplification unit, 34 ...
Transmission control section 41 Smoothing circuit section 42 Serial signal detection section 43
... Filter section, 44 ... Signal demodulation section,
45: error detection unit, 51: parallel conversion unit,
52 ... Output control unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08C 13/00-25/04 H03M 9/00 H04L 25/02

Claims (2)

(57) [Claims] 1. A serial signal transmitting device that receives a parallel signal, converts the parallel signal into a serial signal, and transmits the serial signal, and a serial signal receiving device that converts a serial signal from the serial signal device into a parallel signal. In the serial signal transmission device, the serial signal transmission device includes a serial signal conversion unit that converts a parallel signal that is a data signal into a data signal that is a serial signal, and a power that changes in a constant cycle to the serial signal reception device. Signal generating means for generating a power signal to be supplied, signal modulating means for modulating the data signal and the power signal from the serial signal converting means, and the data signal and the power modulated by the signal modulating means Power capacity increasing means for increasing the power capacity of the modulated signal of the signal; Having, the serial signal receiving device, a power demodulation means for demodulating the modulated signal to the power signal to obtain power, a serial signal detection means for detecting the modulated signal without being affected by the power demodulation means, A serial signal demodulating means for demodulating the modulated signal from the serial signal detecting means to a data signal from the serial signal transmitting device, and a parallel signal for converting the data signal from the serial signal demodulating means to a parallel signal. And a signal conversion unit. 2. An exclusive power signal for converting a parallel signal, which is a data signal, into a data signal, which is a serial signal, and supplying power to the outside together with the converted data signal and the data signal which changes at a constant cycle. Logical modulation is performed, the power capacity of the modulated signal is increased, the modulated signal having the increased power capacity is transmitted to the outside, and the received modulated signal is demodulated to obtain the power and the data signal. A serial signal transmission method comprising converting the obtained data signal into parallel.