JP2956385B2 - Bus line monitoring 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 bus line monitoring system, and more particularly, to a system in which a plurality of units are connected in a bus configuration, wherein a CPU provided in a main unit includes:
The present invention relates to a bus line monitoring method capable of monitoring a failure of a bus line when monitoring a failure alarm or the like of another unit via the bus line.

[0002]

2. Description of the Related Art Conventionally, in this type of bus line monitoring system, as shown in FIG. 2, for example, a main unit 201 and sub units 202 and 20 provided in one device are provided.
3 and 204 are connected by a bus line 207.
Here, the main unit 201 includes the buffer 205 and the CPU 20.
6 and the CPU 206 is a subordinate unit 20
2, 203, and 204 exchange monitoring information and normal data processing information. That is, in the conventional monitoring operation, a dedicated monitoring unit is not provided, and one of the constituent units serves as the main unit 201, and exchanges signals with the subordinate units 202, 203, and 204 sequentially. As a method of monitoring a bus line failure, a bus line failure is detected by determining whether a desired signal is returned from the units 202, 203, and 204 as a response signal to an access signal from the main unit 201. Also,
The central processing unit such as the CPU 206 performs a task of determining a response signal from each unit based on normal data exchange.

[0003]

In the conventional bus line monitoring system described above, since the main unit is mainly used to perform signal exchange with each unit by a CPU or the like to monitor a fault, a low speed processing such as an alarm processing system is performed. When a high-speed signal suitable for the system is used on the common bus line, it is very difficult to monitor the failure of the bus line.
In addition, when a failure occurs in each unit input unit, since the bus configuration is used, it is not possible to identify the failed unit from the main unit side. is there.

[0004]

According to the bus line monitoring system of the present invention, a plurality of units for transmitting and receiving data signals are connected by a bus, and one of the plurality of units has a central processing unit, and other units have ordinary data. In the bus line monitoring method for transmitting and receiving signals, a bus line monitoring code is transmitted to monitor the central processing unit and the bus line failure.
The monitoring code generator and the monitoring code generator
Or select one of the central processing units and
A main unit having a buffer S connected to the
Receiving a signal from the buffer S via the bus line
Receiving the signal from the buffer B and the buffer B,
A bus line monitoring system that recognizes line monitoring code signals
Control unit and the bus line monitoring control unit
All of the plurality of units are synchronized with the timing signals.
Control signal that sends a control signal for
A monitoring unit having a sending unit;
A first control line connecting the monitoring unit;
Branch from the first control line to connect to the plurality of units;
And a second control line that follows .

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of one embodiment of the present invention. In the embodiment of FIG. 1, a monitoring unit 10 is added, and further, a monitoring code generator 21 and a combination logic unit 23 are added to the main unit 1. The subordinate units 2, 3, and 4 are also provided with a monitoring code generator 21 and a combinational logic unit 23, each of which is connected to the monitoring unit 10 by a control line 100.

Next, the operation of this embodiment will be described. Normal data exchange is performed between the main unit 1 and the unit 2, between the main unit 1 and the unit 3, and between the main unit 1 and the unit 4. As a representative example, taking the main unit 1 and the unit 2 as an example, a signal from the unit 2 is sent to the CPU 206 in the main unit 1 through the buffer S22. Conversely, the signal from the main unit 1 is
, And flows into the unit 2 through the bus line 207.

Next, a case in which the monitoring unit 10 performs bus line failure monitoring in this state will be described. The bus monitoring control unit 11 issues an instruction to the control signal sending unit 13 and informs, for example, to the main unit 1 via the control line 100 that the monitoring is desired by the monitoring command signal 102. The combination logic unit 23 has a function of identifying that it is a monitoring command signal for the own unit. The monitoring code generator 21 sends the monitoring code to the monitoring unit 10 via the bus line 207 by the buffer 22 based on the instruction. The control signal sending section 13 outputs a device designation signal 104 for selecting the main unit 1, and as described above, the combinational logic section 23 determines that the main unit 1 is to be used, and switches the gate of the buffer S22 to the open state to switch the monitoring code. Generator 21
Output monitoring code from The monitoring code returns to the buffer B12 via the bus line 207, and the bus line monitoring control unit 11 compares the monitoring code with the monitoring code that has been set, so that the failure of the bus line can be monitored. The monitoring code can be provided independently for each of the units 2, 3, and 4, and it is possible to determine which unit is based on the code value. The monitoring command signal 102 is transmitted at a timing from the point where the timing of the entire system is controlled.
Thus, monitoring can be performed using empty time slots for normal signal exchange between units, and monitoring can be performed using empty time slots even in a considerably high-speed signal system. Further, the buffer S22 is configured by a physical switch such as a relay, and a unit other than the device designated (for example, the units 2, 3, and 4) is electrically disconnected, so that a failure of the bus line is caused by a short circuit of a bus line input unit in the unit. It is also possible to quickly determine the faulty unit even in the state.

As described above, the units 2, 3, and 4 also have the same circuit configuration as the main unit 1 and perform the same operations to monitor the bus line 207 in the units 2, 3, and 4.
Bus line 20
Seven obstacles can be specified.

[0009]

As described above, the present invention is also applicable to a system in which a high-speed signal is exchanged between units by providing a monitoring unit, a monitoring code generator, and a combinational logic unit in each unit. Thus, there is an effect that the bus line can always be monitored by using the empty time slot. Further, by configuring the configuration of the buffer S with a physical switch such as a relay, there is an effect that a faulty unit which has an adverse effect on the bus can be easily identified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional bus line monitoring method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main unit 2, 3, 4 unit 10 Monitoring unit 11 Bus line monitoring control unit 12 Buffer B 13 Control signal transmission unit 21 Monitoring code generation unit 22 Buffer S (bidirectional) 23 Combination logic unit 100 Control line 101 Monitoring timing Signal 102 Monitoring command signal 104 Device designation signal 201-204 Unit 205 Buffer 206 CPU 207 Bus line

Claims (2)

(57) [Claims] 1. A bus line monitoring system in which a plurality of units for transmitting and receiving data signals are connected by a bus, and one of the plurality of units has a central processing unit and exchanges normal data signals with other units. The central processing unit and a bus line monitoring command for monitoring the bus line failure.
Monitoring code generator for sending code and the monitoring code
Select either the generating unit or the central processing unit and
Main unit having buffer S connected to bus line
And a signal from the buffer S via the bus line.
Receiving buffer B and the signal of buffer B
A bus line for recognizing the bus line monitoring code signal
The monitoring control unit and the bus line monitoring control unit
The plurality of units in accordance with external timing signals.
Sends control signals for all units
A monitoring unit having a control signal transmitting unit;
First control line connecting the monitoring unit with the monitoring unit
Branching from the first control line and
And a second control line connected to the bus. 2. In a state where a normal data signal is transmitted and received between a main unit having the central processing unit and another unit, the control signal transmitting unit uses a free time slot to control the control line. 2. The bus line monitoring system according to claim 1, wherein a control signal is transmitted to each unit connected through the bus.