JP2000031839A - Highly reliable data transmitter and system therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent data from being erroneously transmitted even when power is inputted by providing a data transmission inhibit circuit which allows data to be transmitted until an power output is stabilized and performing the connection/disconnection of a signal line that connects a semiconductor relay with a receiver and a transmission driver when an output of a data output inhibit circuit is on. SOLUTION: As power VCC is fed, a data transmission inhibit signal becomes a higher level, a circuit (203) is turned on at certain voltage. The data transmission inhibit signal is on a low level and a power supply unit 120 is not turned on until power VCC voltage becomes stable. Even if the data transmission inhibit signal 101 becomes on at that time, a circuit (207) is prevented from being turned on because a signal line becomes a low level due to a circuit (203). A timing circuit makes the timing in which a semiconductor relay 106 is turned on delayed more than a semiconductor relay 105 and the relay 106 disconnects a signal line 109 even in a transient state when power supply is turned on/off by a transmission driver by making off timing early.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device having a transmission driver for transmitting data to another device via a signal line and a control circuit therefor. The present invention relates to a highly reliable data transmission device that does not transmit erroneous data.

[0002]

2. Description of the Related Art In recent years, the reliability of a data transmission / reception device has increased with the development of a network society, and erroneous data is transmitted due to a failure of the data transmission device, which may cause a malfunction of a receiving side system, or cause a data transmission error. This has a great effect such as making transmission impossible, and requires high reliability of the data transmission device. Therefore, a highly reliable data transmission device that does not transmit erroneous data to the receiving side when the power supply becomes unstable or when a failure occurs is required.

Conventionally, as a means for realizing a highly reliable data transmission device, there is a method of controlling connection / disconnection of a signal line using a mechanical relay.

[0004]

However, in the above-mentioned prior art, the connection / disconnection of the signal line is performed using a mechanical relay, so that the mounting space in the device becomes large, and the connection / disconnection is large. Current must be passed, and it takes time to connect / disconnect. Also,
Even if the mounting space is smaller than a mechanical relay and it is replaced with a semiconductor relay that can be driven with a small current, the same method as a mechanical relay will cause
In a transient state at the time of power-on, there is a possibility that a signal line is connected and erroneous data is transmitted.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, so that erroneous data is not transmitted from a signal line even in a transient state at the time of power-on, mounting efficiency is increased, and power consumption is reduced. And a highly reliable data transmission apparatus and method.

[0006]

In order to achieve the above object, a highly reliable data transmission apparatus and method according to the present invention provides a stable power output by generating a data transmission suppression signal by a power determination signal from a power supply. A data transmission suppressing circuit that does not turn on a data transmission permission signal that permits data transmission, and a semiconductor for turning off a power supply of a transmission driver that transmits data when an output of the data transmission suppressing circuit is on. By providing / removing a relay and a signal line connected to a receiving device and a transmission driver, and providing a semiconductor relay that disconnects when the output of the data transmission suppression circuit is on, erroneous data can be transmitted to the signal line. It is not transmitted.

That is, in the highly reliable data transmission apparatus and method of the present invention having the above-described configuration, the mounting space can be reduced by using a semiconductor relay instead of a mechanical relay, and the power supply is started by providing a signal transmission suppression circuit. In the transient state, transmission of erroneous data to the signal line with other devices is suppressed, and the power supply of the transmission driver is turned off when the signal line is disconnected, so the relay on the signal line side is fixed in the connected state Do not send erroneous data to the outside even if a failure occurs.

[0008]

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a data transmission device according to one embodiment. 100 is a data transmitting device, and 120 is a power source (V
CC) and a power supply device for transmitting a power supply confirmation signal 122, 13
Reference numeral 0 denotes a data receiving device that receives data transmitted from the data transmitting device 100 via the signal line 109.

The data transmission device 100 includes a data transmission permission signal (negative logic) 101, a data transmission control circuit 102, a transmission driver power control signal 103, a semiconductor relay 105 for turning on / off the power of the transmission driver by the signal, and a data transmission. A signal line connection signal 104 and a semiconductor relay 106 for connecting / disconnecting a data signal line based on the signal, a data transmission driver 107, a power supply line 108 for supplying power to the transmission driver, and a data connection device 10
9, transmission data generation circuit 110, error detection circuit 111
It consists of.

Next, the configuration of the data transmission control circuit 102 in the data transmission device 100 will be described in detail with reference to FIG. First, the operation of the data transmission control device when the power supply device 120 is stabilized and normal data transmission is performed will be described. At this time, the power determination signal 122 is on (low level), and the data transmission suppression signal (negative logic) 204 is off (high level). When the data transmission permission signal 101 is turned on (low level) in this state, the signal line 202 becomes high level, and the signal lines 202 and 204 are wired-OR in the circuit 205. Therefore, the signal line 206 is low level and the circuit 207 is turned on. Semiconductor relays 105 and 10
6 is also turned on, and data is transmitted. Similarly, when the data transmission permission signal 101 is turned off (high level), the signal line 202 becomes low level. At this time, the data transmission suppression signal 204 is at a high level, but is wired-ORed by the circuit 205, and thus is dropped to a low level by the circuit 201. As a result, the signal line 206 is at a low level, the circuit 207 is turned off, and the semiconductor relay is also turned off, so that no data is transmitted.

Next, an operation in a transient state in which the power supply device 120 starts up will be described with reference to FIG. First, the configuration of FIG. 4 is provided as an example of realizing the power supply determination signal. As the power supply (VCC) is supplied from the power supply device 120, the data transmission suppression signal 204 also goes high, but when a certain voltage is reached, the circuit 203 turns on. At this time, since the voltage of the circuit 207 is divided by the signal line 209, the voltage does not reach the ON voltage. Therefore, the data transmission suppression signal 204 becomes low level, and the circuit 120 will not turn on until the voltage of VCC becomes stable in the future.

Further, when the transmission suppression signal 204 is on (low level), the signal line 202 is low by the circuit 203 even if the data transmission permission signal 101 is on, so that the circuit 207 cannot be turned on. Absent. This prevents erroneous data from being transmitted even in a transient state when the power is turned on. The timing of turning on the semiconductor relay 106 by the timing circuit 208 is delayed from that of the semiconductor relay 105, and the timing of turning off the semiconductor relay 106 is advanced, so that the transmission driver 107 can respond to the transient state when the power is turned on / off. 1
Since the signal line 109 is disconnected by 06, transmission of erroneous data is prevented. Of course, the present invention can also be realized by using a commercially available voltage monitoring circuit instead of the power supply determination signal from the power supply device. Further, even when the semiconductor relays 105 and 106 are momentarily turned on due to noise or the like, erroneous data is not transmitted to the signal line because the power of the transmission driver is not supplied.

When a failure of the transmission driver is detected by the error detection circuit 111 (for example, realized by a comparison check with the original data: FIG. 5), by turning off the data transmission permission signal, an error in the failure of the transmission driver is detected. To prevent the transmission of lost data. Hereinafter, an embodiment that is a modification of the first embodiment will be described. FIG. 6 shows a first embodiment in which power supplies to the data transmission control circuit and the transmission driver are individually provided. Thus, it is possible to prevent the power supply fluctuation on the control circuit side from affecting the reception side. 1
Reference numeral 20 denotes a power supply (V) through a power supply line 121 to the data transmission control circuit 102 in the data transmission apparatus 100.
CC1) and a power supply device that outputs a power supply determination signal 122 to the data transmission suppression circuit.
And a data transmission permission signal for outputting a power determination signal 142 to the OR circuit 150. Power supply 12
The data transmission operation when the power supplies 0 and 140 are stable is the same as in the first embodiment.

Next, when the power supply device 120 is stable and the power supply device 140 starts up, the power supply confirmation signal 142 controls the data transmission permission signal by the OR circuit. , Transmission permission is not turned on. When the power supply device 140 is stable and the power supply device 120 starts up, the operation is the same as in the first embodiment.

An embodiment to which the first embodiment is applied will be described below. FIG. 7 shows a working / spare configuration in which the data transmitting apparatus of the first embodiment is duplicated and connected to another apparatus via one signal line. When one of the systems 710 fails, the data signal line is disconnected by turning off the semiconductor relays 711 and 712, and the semiconductor relay of the other system 720 is turned on. , Data transmission can be continued.

[0017]

According to the present invention, it is possible to use a semiconductor relay in a data transmission device requiring high reliability, to reduce a mounting space, and to suppress power consumption.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a reliable data transmission device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a data transmission control circuit of FIG. 1;

FIG. 3 is a time chart of a data transmission suppression signal at power-on.

FIG. 4 is a circuit diagram showing a configuration example of a power supply determination signal.

FIG. 5 is a circuit diagram showing one embodiment of an error detection circuit.

FIG. 6 is a configuration diagram of a system according to an embodiment in which the first embodiment is modified.

FIG. 7 is a system configuration diagram to which the first embodiment is applied.

[Explanation of symbols]

100 data transmission device, 106 semiconductor relay, 12
0: power supply device, 121: power supply line.

Continued on the front page (72) Inventor Kazuhiro Hinata 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture F-term in the Omika Plant of Hitachi, Ltd. F-term (reference) 5K021 AA06 CC01 DD02 EE07 FF01 FF12 5K060 BB05 CC01 CC11 CC17 GG03 HH33 HH34 HH39 JJ06 JJ23 LL04 LL12 MM06 PP03

Claims (2)

[Claims] 1. A data transmission device having a transmission driver for transmitting data to another device via a signal line and a control circuit therefor, wherein a data transmission suppression signal is generated by a power supply determination signal from a power supply device, thereby providing a power supply. A data transmission suppression circuit that does not turn on a data transmission permission signal that permits data transmission until an output is stabilized; a semiconductor relay that turns off a transmission driver when an output of the data transmission suppression circuit is on; By providing a semiconductor relay for connecting / disconnecting a signal line from a driver to an external device and disconnecting when the output of the data transmission suppression circuit is on, a signal line with another device in a transient state at power-on is provided. A highly reliable data transmission device that prevents erroneous data from being transmitted. 2. A data transmission apparatus according to claim 1, wherein said data transmission apparatus is duplexed and one of said systems fails in a working / spare configuration in which connection with another apparatus is performed via one signal line. However, a highly reliable data transmission method characterized in that the data transmission is continued by the other system without adversely affecting the signal line by being disconnected by the semiconductor relay.