JPH0521466B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to an abnormality occurrence signal transmission device, and in particular,
This is suitable for application to transmit a power outage signal to a receiving station when a power outage occurs at a transmitting station.

(Prior Art) Conventionally, various transmission devices have been proposed that transmit a power outage signal when a power outage abnormality occurs at a transmitting station so that the receiving station can distinguish it from other abnormalities such as equipment malfunction or line disconnection. .

For example, first, an emergency power supply is installed at the transmitting station that can supply power for a certain period of time in the event of a power outage, and in the event of a power outage, a specific pattern generation circuit receives power from the emergency power supply and generates a specific pattern of several bits. A transmission device has been proposed in which the receiving station determines a power outage by detecting this specific pattern.
-229441).

However, according to this device, in order to generate a specific pattern of several bits, that part is actually composed of an oscillation circuit, a shift register, a gate circuit, and the receiving section is also actually composed of an oscillation circuit, a shift register, a comparison circuit, etc. However, due to the rare occurrence of situations, the overall configuration of the device becomes large and complicated.

Furthermore, a second transmission device has been proposed that transmits a power outage signal by transmitting only data at a predetermined logic level as long as the auxiliary power supply continues to supply data at the time of a power outage.

However, according to this method, a repeater is installed on the transmission path, and when the line is disconnected, the receiving station receives only data at a predetermined logic level from the repeater, so there is no risk of a power outage at the transmitting station. It is not possible at the receiving station to distinguish whether this is due to a disconnection or a disconnection of the line.

(Problems to be Solved by the Invention) As mentioned above, when transmitting an abnormality signal (for example, a power outage signal) using a conventional transmission device, the configuration of the entire device is large and complicated, or the logic level is fixed. If an attempt was made to transmit the signal using a simple configuration, there was a problem in that the abnormality signal could not be transmitted accurately. Further, there was a problem in that the receiving station could not distinguish between an abnormality at the transmitting station and an abnormality such as a disconnection of the transmission line.

SUMMARY OF THE INVENTION An object of the present invention is to provide an abnormality signal transmission device with a simple configuration that can reliably transmit an abnormality signal notifying an abnormality occurring at a transmitting station to a receiving station.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the abnormality occurrence signal transmission device according to the present invention has a transmitting station that transmits a signal when an abnormality occurs in the transmitting station. , an abnormality detection means that detects this and stops outputting the transmission information signal, and a constant logic level that is operated by an auxiliary power source and has a T1 time width longer than the longest time that the transmission information signal can take the same logic level. and an abnormality occurrence signal transmission means for repeatedly transmitting an abnormality occurrence signal, which is a pair of a signal and a signal obtained by inverting this signal, to a receiving station, and the receiving station side has an abnormality occurrence signal that is shorter than the T1 time and transmits the transmission information. a timing means for timing a T2 time longer than the maximum time during which the signal can assume the same logic level; and if the signal is received within this T2 time;
The present invention is characterized by comprising a determining means that determines that a transmission information signal has been received, and determines that an abnormality occurrence signal has been received when a signal that repeats inversion at least twice after T2 time has elapsed is received.

(Function) According to the above configuration, when an abnormality is detected on the transmitting station side, the output of the transmission information signal is stopped, and a signal of a constant logic level having a time width of T1 and a signal obtained by inverting this signal are output. A pair of abnormality occurrence signals are repeatedly transmitted to the receiving station.

On the receiving station side, if the signal is received within time T2, which is shorter than time T1 and longer than the maximum time during which the transmitted information signal can have the same logic level,
While it is determined that a transmission information signal has been received, it is determined that an abnormality occurrence signal has been received when a signal that repeats inversion at least twice after T2 time has elapsed.

Therefore, the abnormality occurrence signal from the transmitting station can be reliably transmitted to the receiving station with a simple configuration without being mistaken for an abnormality occurring in the transmission path.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, a transmitting station 1 and a receiving station 2 are connected via a transmission line 3. In FIG. The transmitting station 1 includes an information transmitting section 4 that outputs a transmission information signal INF, and a power outage signal generating section 6 that receives power from an auxiliary power source 5 made of a capacitor and generates a power outage signal. The transmission information signal INF from the information transmitter 4 and the power outage signal STP from the power outage signal generator 6 are sent to the switch circuit 7.
is selected and given to the double-current sending unit 8, converted into a double-current signal of a predetermined level, and output to the transmission line 3. The switch circuit 7 is normally connected to the information transmitter 4
It is connected to the power outage signal generating section 6 side, and is switched to the power outage signal generating section 6 side in response to a detection output from a power outage detection section 9 that detects a power outage of the main power source.

The power outage detection unit 9 and the switch circuit 7 are, for example,
It can be configured with a relay that energizes the contact toward the information transmitting unit 4 side when power is supplied and its contact.

The power outage signal generating section 6 is composed of a timer 6a that measures a predetermined time T1, and an inversion circuit 6b that inverts the logic level every predetermined time T1, and generates a pulse signal with a period twice the predetermined time T1 as a power outage signal STP. occurs as. Specifically, as shown in FIG. 2, a power outage signal generating section 6 in which a timer 6a and an inverting circuit 6b are integrated can be realized by a non-multivibrator circuit using an operational amplifier OP1.

Here, the predetermined time T1 is selected to be longer than the longest time during which data at the same logic level continues during transmission of the transmission information signal INF. In practice, a start bit and a stop bit are inserted as shown in Figure 3 to distinguish between characters (e.g. 8 bits), so the same logic level continues for a longer period of time than it takes to reach the next character. Therefore, the predetermined time T1 is selected to be longer than this.

Corresponding to the above-described configuration of the transmitting station 1, the receiving station 2 has the following configuration:
It has the following configuration. The transmission information signal INF or power outage signal STP arriving from the transmission path 3 is sent to the double-current receiver 1
0, and after level conversion, is provided to the information receiving section 11 and the power outage signal detecting section 12. The information receiving section 11 receives the transmission information signal from the information transmitting section 4.
It demodulates the INF, and the power outage signal detection unit 12
is to demodulate and detect the power outage signal STP from the incoming signal.

The power outage signal detection unit 12 includes an edge separation circuit 12a that extracts the edge portion of the incoming signal, and a retrievable timer 12b that inverts the logic level after a predetermined time T2 after receiving the edge signal ED.
A pulse number detection circuit 12c detects that there are two or more pulse signals TOUT from the timer 12b.
It is made up of.

The edge separation circuit 12a, as shown in FIG.
The incoming signal REC (Fig. 5A) is slightly integrated by the integrator circuit 13.
and the delayed arriving signal RECD (fifth
The exclusive OR circuit 14 obtains the exclusive OR of the arrival signal REC before the delay and the transmission information signal INF and the power outage signal.
The edge signal ED (FIG. 5C) is obtained by extracting the edge portion regardless of the STP portion.

As shown in FIG. 6, the timer circuit 12b is constituted by an unstable multivibrator circuit using an operational amplifier OP2. Here, the predetermined time T2 is selected to be shorter than the time T1 during which the power outage signal STP remains at the same level, and longer than the longest period during which the transmission information signal INF continues to have bits at the same level. Therefore, during the period in which the transmission information signal INF is arriving, the next edge signal ED arrives and is triggered before the predetermined time T2 is counted, so the timer circuit 12b does not invert its output level; power outage signal
When STP arrives, a predetermined time T2 is counted and the output level is inverted. Since the power outage signal STP inverts its logic level at least twice every predetermined time T1, the timer circuit 12b also inverts the logic level for the predetermined time T1.
Outputs a pulse signal TOUT that rises every T1.

As shown in FIG. 7, the pulse number detection circuit 12c detects the edge signal ED (FIG. 8A) and the timer 12b.
It consists of an AND circuit 15 that obtains an AND output with the output signal TOUT (FIG. 8B), and a lip counter 16 in which D-type flip-flop circuits 16a and 16b are connected in cascade.
The falling edge of the output signal b is extracted, and the counter 16 counts the number of extracted edge signals. Here, D of 2LSB
Q output 16b of type flip-flop circuit 16b
(D in FIG. 8) is applied to its own set terminal, so that when the number of pulses of the output signal of timer 12b is counted to 2, the Q output Q16b maintains its logic level from then on. ing.

In the above configuration, when power is normally supplied to the transmitting station 1, the transmission information signal INF output from the information transmitting section 4 is given to the double current transmitting section 8 via the switch circuit 7, and the level is converted. Thereafter, the signal is outputted to the transmission path 3, taken in by the double-current receiving section 10 of the receiving station 2, level-converted, and given to the information receiving section 11, where it is demodulated.

On the other hand, when a power outage occurs in the main power supply at time t1 shown in FIG. As shown in Figure 9B, during time T1, instead of the transmission information signal INF,
Take one logic level (“L”) and then time
During T1, a power outage signal STP that takes the other logic level (“H”) is output.

Thus, at the receiving station 2, the received signal REC as shown in FIG. 9C is transmitted to the edge separation circuit 12A.
and the edge signal as shown in Figure 9D.
ED is given to timer 12d. As a result, the timer 12b outputs the output signal TOUT (FIG. 9E) with the cycle T1 and the falling period T2 after time t1, and the pulse number detection circuit 12c outputs the output signal TOUT.
Power outage detection signal DET (9th
Start up Figure F).

In this way, the occurrence of a power outage at the transmitting station 1 can be transmitted to the receiving station 2.

According to the above-described embodiment, a simple pattern in which the logic level is inverted every predetermined time T1 is used as the power outage signal pattern. can be transmitted. Further, since the logic level is inverted to obtain a power outage signal, the power outage signal can be detected at the receiving station 2 even when a repeater or the like is installed.

In the above embodiment, the abnormality signal to be transmitted is a power outage signal, but it may be any other abnormality signal. It is also possible to allocate and transmit the corresponding information.

Furthermore, in the above embodiment, the timers 6a and 12b were configured with unstable multivibrators using operational amplifiers OP1 and OP2, but
Crystal oscillator as shown in Figures 10 and 11
The oscillation outputs from the original oscillators 20 and 21 using Xtal1 and Xtal2 may be divided by the counters 22 and 23 to form the predetermined times T1 and T2. In this case, since the timer 12b is retriggerable, it is necessary to apply the edge signal ED to the reset terminal of the counter 23.

[Effects of the Invention] As explained above, according to the present invention, with a simple device configuration, an abnormality occurrence signal that notifies an abnormality that has occurred in a transmitting station can be reliably received without being mistaken as an abnormality that has occurred in a transmission path. It can be transmitted to the station.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the abnormality signal transmission device according to the present invention, FIG. 2 is a connection diagram showing the detailed configuration of the power outage signal generating section 6, and FIG. 3 is for explaining the predetermined time T1. A schematic diagram, FIG. 4 is a connection diagram showing the detailed configuration of the edge separation circuit 12a, and FIG.
6 is a connection diagram showing the detailed configuration of the timer 12b, FIG. 7 is a block diagram showing the detailed configuration of the pulse number detection circuit 12c, FIG. 8 is a timing chart of each part, and FIG.
The figure is a timing chart of each part of the transmission device in Figure 1, and Figures 10 and 11 are each a timer 6a.
and 12b is a block diagram showing another example. 1... Transmitting station, 2... Receiving station, 3... Transmission line,
5... Auxiliary power supply, 6... Power outage signal generator, 7...
Switch circuit, 9...Power failure detection unit, 12...Power failure signal detection unit.

Claims (1)

[Claims] 1. On the transmitting station side, if an abnormality occurs in the transmitting station, an abnormality detection means detects the abnormality and stops outputting the transmission information signal, and the abnormality detection means is operated by an auxiliary power source and T1 longer than the maximum time that an information signal can have the same logic level
an abnormality occurrence signal transmission means for repeatedly transmitting an abnormality occurrence signal, which is a pair of a signal of a fixed logic level having a time width and a signal obtained by inverting this signal, to a receiving station; a timer for timing T2 time which is shorter than time and longer than the maximum time during which the transmission information signal can take the same logic level; and when a signal is received within this T2 time,
An abnormality occurrence signal characterized by comprising: determination means that determines that a transmission information signal has been received, and determines that an abnormality occurrence signal has been received when a signal that repeats inversion at least twice after T2 time has elapsed is received. Transmission device.