JPS5813052B2 - Abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormality detection device for detecting an abnormality in a slave station in a signal transmission system consisting of a master station and a plurality of slave stations and returning an abnormality detection signal to the master station.

Generally, in the above signal transmission system, if the master station and each slave station are located at a distance, it may be difficult to detect abnormal failures in each slave station.

Therefore, each slave station is equipped with a self-diagnosis function, and when an abnormal failure occurs, this is sent back to the master station.

Figure 1 shows a conventional device of this kind, where 100 is a master station, 2
00, 201, and 202 are slave stations, respectively, and are connected to the master station by signal lines indicated by solid lines.

The abnormality detection signal from each slave station is sent back to the master station through signal lines indicated by dotted lines that connect each slave station and the master station.

However, each slave station requires a return line for abnormal failures, which increases the number of lines.

In addition, FIG. 2 shows the master station 100 and each slave station 200, 201, 20.
In this case, a master station 100 and slave stations 200, 201 are connected by a multiplex signal transmission system.
, 202 (solid lines) are reduced as shown in the figure.

However, since each slave station 200, 201, 202 and the master station are wired one-to-one using a signal line (dotted line) dedicated to abnormality detection, the number of wires increases.

Furthermore, FIG. 6 shows the master station 100 and each slave station 200, 20.
1,202 are connected by multiplex signal system, and each slave station 200,2
A conventional example is shown in which abnormality detection signal lines (dotted lines) of 01 and 202 are wired-OR connected and sent back to the master station 100.

In this example as well, the master station 100 communicates with each slave station 200, 201, 200, 200, 201, 200,
Send a signal to 2.

On the other hand, if an abnormality occurs in any of the slave stations 200, 201, and 202, a message indicating that one of the slave stations is abnormal is sent to the master station 100 via the wired-OR connected abnormality detection signal line (dotted line). Let me know.

In this example, the number of wires is further reduced than in the conventional example shown in FIG. 2 by connecting the abnormality detection signals of each slave station 200, 201, and 202 by wire-OR connection.

However, by doing so, even if the master station 100 can detect that an abnormality has occurred in one of the slave stations 200, 201, and 202, it cannot identify which slave station it is. .

However, as seen in this example, even if the master station 100 cannot specifically identify the child station in which the abnormality has occurred, it may be sufficient to detect that the abnormality has occurred in one of the child stations.

For example, if the master station 100 is installed at a long distance from the slave stations 200 to 202, and the slave stations 200, 201, and 202 are installed in one place, the master station 100 , 201, 202 and displays the error, the user can
It is possible to go to the location where 02 is installed and discover the slave station (any one of 200 to 202) in which an abnormality has occurred.

At this time, if the slave station in which the abnormality has occurred displays this fact, the user can easily identify the slave station in which the abnormality has occurred.

In this way, one dedicated signal line for abnormality detection is sufficient, but such a signal line is still necessary.

This invention was made in view of these points,
There is no need to install a dedicated signal line for abnormality detection between the master station and slave stations.
The present invention provides an abnormality detection device that can confirm and detect whether there is an abnormality in any one of a plurality of slave stations.

Next, embodiments of the invention will be described.

FIG. 3 is a block diagram showing an embodiment of the invention.

In the figure, 210, 211, 212 and 213 each indicate a slave station.

This embodiment shows an example in which the present invention is applied to a signal transmission system in a multiplexed signal transmission format.
3 through the same signal line, only a small number of signal lines are required.

In this case, the abnormality detection signal output lines of slave stations 210, 211, and 212 are wired OR-connected and connected to slave station 213 (indicated by dotted lines in the figure).

Then, the abnormality detection signals of each slave station are collected from the slave station 213 and sent back to the master station 100 via the signal line.

Therefore, the master station 100 can confirm and detect an abnormality in any of the slave stations 210 to 213.

Wiring for abnormality detection can be done between slave stations 210 and 213.
There is no need between the master station 100 and the slave stations 210 to 213.

FIG. 4 is a circuit diagram showing an example of a specific circuit configuration shown in FIG. 3 above.

In the figure, 10, 11, 12, and 13 are PNP transistors, and a signal is sent to each base to notify the outside of the slave stations of an abnormality that has occurred inside the slave stations 210 to 213 (hereinafter referred to as the slave station abnormality signal). (to be distinguished from the above-mentioned abnormality detection signal) is applied.

14, 15 and 16 are resistors, and 17 is an NPN transistor, respectively.

If the slave station 210 becomes abnormal, the base current of the transistor 10 flows, the transistor 10 becomes conductive, and the collector potential rises to the power supply potential.

Then, the base current of transistor 17 is supplied through resistor 14, and transistor 17 becomes conductive.

Therefore, the collector potential of the transistor 17 changes from the power supply potential to the ground potential, and this collector potential can be used as an abnormality detection signal and sent back to the master station 100.

In the above description, the short circuit between the emitter and collector of the transistors 10 to 13 is to notify that the slave station is in an abnormal state, and the abnormal state is occurring elsewhere.

That is, the configuration of the slave stations 210 to 213 shown in FIG. 4 will be explained in more detail as shown in FIG. 7.

In the figure, 20 to 23 are lamps, and 24 is a control circuit.

The slave stations 211 and 212 have the same configuration as the slave station 210.

Now, the control circuit 24 of each slave station 210 to 213 decodes the multiplexed signal transmitted from the master station, extracts a signal component corresponding to the slave station to which it belongs, and controls the lamps 20 to 23 based on the signal component. It has the ability to selectively turn on or off.

Furthermore, if any of the lamps 20 to 23 fails due to filament breakage, etc., the slave station abnormality signal 24a is set to the ground potential, and for example, the transistor 10 of the slave station 210 is made conductive.

If there is no failure (or abnormality), the slave station abnormality signal 24a is kept at the power supply potential and the transistor 10 is in a non-conductive state.

When the above-mentioned failure occurs in any of the slave stations 210 to 213, the transistor (for example, 10) becomes conductive.The transistor 17 of the slave station 213 becomes conductive, and the signal line from the master station 100 is kept at ground potential. It will be dripping.

Therefore, by detecting that its own signal line is always at ground potential, the master station 100 can know that one of the slave stations is out of order.

To further supplement the above explanation, regarding the slave station 210, the part of the control circuit 24 that outputs the slave station abnormality signal 24a and the circuit formed by the transistor 10 form the slave station abnormality detection circuit that outputs the slave station abnormality detection signal. It consists of

Note that the same applies to slave stations 211, 212, and 213.

In addition, a circuit using a transistor 17 provided in the slave station 213 connects the output of the wired-OR circuit in which the output line of the slave station abnormality detection circuit is wired-OR connected to the same signal line connecting the master station and each slave station. It operates as a transmitter circuit for transmitting data.

FIG. 4 shows an embodiment of the present invention in a multiplexed signal transmission system, and FIG. 5 shows an example of a time-division signal in the case of time-division multiplexed signal transmission.

That is, when applying the pulses shown in FIG. 5, the control circuit 24 of each slave station 210 to 213 selects the slave station to which it belongs from the time division multiplexed signal (A in FIG. 5) transmitted by the master station 100. A signal corresponding to is extracted, and predetermined lamps 20 to 23 are turned on or off based on this signal.

Furthermore, the control circuit 24 controls the lamp 2 as in the previous embodiment.
0 to 23, etc., and controls the transistor 10 of the slave station 210, for example.

In this case, in the time division multiplexed signal A, each pulse 1 to 4 is assigned an order based on a pulse (not shown) indicating a reference time, and for example, pulse 2 is used as a pulse signal for abnormality detection. , the master station 100 always outputs H level pulse 2 (FIG. 5B) in this order.

On the other hand, if the control circuit 24 of each slave station 210 to 213 does not detect an abnormality, the slave station abnormality signal 24a is always kept at the power supply potential, so that each transistor 10 to 13 becomes non-conductive, and therefore transistor 17 also becomes non-conductive. , master station 100
By detecting that pulse 2 is at H level, it can be known that none of the slave stations 210 to 213 is in an abnormal state.

For example, when an abnormality is detected by the control circuit 24 in the slave station 210, the control circuit 24 transmits the slave station abnormality signal only while the transmission signal from the master station 100, that is, pulse 2 of the time division multiplexed signal A, is generated. 24a is grounded and the transistor 10 is made conductive, the transmitted signal from the master station 100 becomes L level as shown in FIG. 100 can detect that an abnormality has occurred in any of the slave stations 210 to 213.

As described above, the control circuit 24 of the slave station 210 turns on the transistor 10 only while the pulse 2 of the time division multiplexed signal A is generated, and turns on the transistor 10 in the slave station while the other pulses 1, 3, and 4 are generated. Since the abnormal signal 24a is kept at the power supply potential and the transistor 10 is made non-conductive, the transistor 17 of the slave station 213 becomes non-conductive, and the master station 100 can normally transmit the signal.

As described above, when a time division multiplexed signal is used as the transmission signal of the master station 100, the master station 100 monitors the state of pulse 2 at a specific time to
Since signals are normally transmitted to these slave stations 210 to 213 while determining whether any one of the slave stations 213 is abnormal or whether all of them are normal, the slave stations that are not abnormal can perform predetermined operations as usual.

Therefore, in the embodiment of the invention shown in FIG.
The collectors of transistors 10 to 13 for outputting an abnormality detection signal built in the terminals 0 to 213 are wired OR connected, and the slave station 213 is used to send the abnormality detection signal back to the master station 100 via a signal line.

Therefore, special signal lines and wiring for abnormality detection are not required.

As described above, according to the present invention, an abnormality detection signal from any slave station in which an abnormality has occurred can be returned to the master station without providing a dedicated signal line for abnormality detection between the master station and the slave stations. This has the effect of saving wiring and shortening the wiring work period.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing a conventional device, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. 4 is a circuit showing an example of the specific circuit configuration of FIG. 3 above. Figure 5 is a diagram showing an example of the signal, Figure 6 is a diagram showing a conventional example in which the abnormality detection signal of each slave station is wired-OR connected and then sent back to the master station, and Figure 7 is a diagram showing an example of the signal. FIG. 2 is a configuration diagram for explaining in more detail the internal configuration of each slave station in the figure. In the figure, 100 is a master station, 210 to 213 are slave stations, and 10
~13 is a PNP transistor, 14 to 16 are resistors, 17
is an NPN transistor. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 In an abnormality detection device that detects an abnormality in a slave station in a signal transmission system configured by connecting a master station and a plurality of slave stations with the same signal line, a slave station abnormality detection circuit that outputs an abnormality detection signal within the station;
A wired-OR circuit in which the output line of the internal abnormality detection circuit in the slave station is wired-OR connected, and a transmission circuit provided in any one of the slave stations to transmit the output of the wired-OR circuit to the same signal line. An anomaly detection device characterized by: