JP2001327188A - Self-diagnostic method for motor control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control system having a function of self-diagnosing a bus connection of the system without providing a test special purpose check land and an I/O and a function of specifying a fault position of a component, a signal line or the like from a self-diagnosing result. SOLUTION: A self-diagnostic method for the motor control system comprises a first step of outputting an L potential by setting I/O ports 31-3X to an output port, then a second step of switching the ports 31-3X to an input port, a third step of waiting a delay time of time constants of pull-up resistors 41-4X, and a fourth step of checking inputs of the ports 31-3X. In the fourth step, if the resistors 41-4X are normally connected, the inputs of the ports 31-3X are changed to an H potential by the pull-up resistors. Accordingly, it is determined to be normal. If there is a disconnection or a short circuit with the L potential, the L potential remains as it is, and the fault can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention mainly relates to one or more L
The present invention relates to a failure diagnosis of an industrial motor control system such as an FA application including an SI and a single-chip microcomputer.

[0002]

2. Description of the Related Art Conventionally, a motor control system in which one LSI and a single-chip microcomputer are connected by a bus has been realized with a configuration as shown in FIG. 6, and a check land dedicated for testing is provided on a printed circuit board. The signal during operation was tested with a special jig.

In FIG. 6, a single chip microcomputer 1
Are connected to the peripheral LSI 2 and are composed of pull-up resistors 41 to 4X for stabilizing the potential when the bus signal is Hi-Z and check lands 51 to 5X for testing. The area of the check land itself must be secured on the printed circuit board by laying out the wiring of 5X from the check land 51, and there is a problem that it is difficult to increase the number of bits of the bus and to reduce the size of the system.

On the other hand, J using serial communication
TAG / Boundary Scan technology has been proposed,
The realization requires dedicated I / O, and most of the components constituting the system must be compatible with JTAG. The increase in the number of I / Os increases the size of the system, increases the cost, and adds new components. There were other problems, such as a longer development period due to adoption.

Further, the power supply to be connected is turned on / off,
A method of judging a normal state or an abnormal state when the switch is turned on (for example, JP-A-11-118864), an input signal and an output signal for a test provided across a connector,
A method of checking by the signal propagation (for example,
No. 75814) has been proposed, but in any case, there is a problem in that a system for self-diagnosis is required, so that the system becomes large and the cost is increased.

[0006]

In the above-mentioned conventional configuration,
The wiring of the check lands and the area of the check lands themselves must be secured on the printed circuit board, and there is a problem that it is difficult to increase the number of bits of the bus and reduce the size of the system.

[0007] Even if a method such as JTAG / boundary scan is introduced, its implementation requires a dedicated I / O or component, resulting in an increase in system size and cost.
There was a problem that the development period was prolonged due to the adoption of new parts.

[0008] Further, only a test in the test process leads to a malfunction of the system even when a part of the failure occurs in the life cycle, and it is difficult to specify the location of the failure.

The present invention has been made to solve the above-mentioned conventional problems, and has a function of performing a self-diagnosis of a system connection without providing a check land or an I / O dedicated to a test, and a self-diagnosis during a life cycle. It is an object of the present invention to provide a motor control system having a function to perform and a function to specify a failure location such as a component or a signal line from a result of a self-diagnosis.

[0010]

According to the present invention, there is provided a motor control system comprising a system in which one or more LSIs are connected to a single-chip microcomputer by a bus. Switch the bus signal pin to an input / output port,
A first step of outputting a potential, a second step of subsequently switching the input / output port to an input port, a third step of waiting for a time for the potential of the input / output port to stabilize, and a step of reading the potential of the input / output port. 4 steps,
The self-diagnosis is performed from the result of the fourth step, and the bus connection between the single-chip microcomputer and the LSI can be self-diagnosed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above problems, the present invention relates to a motor control system comprising a system in which one or more LSIs are connected to a single chip microcomputer by a bus. A first step of switching the pin to the input / output port and outputting the L potential or the H potential, a second step of subsequently switching the input / output port to the input port, and a third step of waiting for a time for the potential of the input / output port to stabilize. And a fourth step of reading the potential of the input / output port. A self-diagnosis method for a motor control system that performs a self-diagnosis based on the result of the fourth step.
Single-chip microcomputer and LSI without / O
Self-diagnosis of the state of the bus connection with the device.

In the fourth step, the motor control system according to claim 1, wherein if the potential is specified by a pull-up resistor or a pull-down resistor, it is determined to be normal, and if not, it is determined to be abnormal. This is a diagnostic method that can detect disconnection or short circuit in the connection state.

4. The self-diagnosis method for a motor control system according to claim 1, wherein in the fourth step, if the potential of the adjacent signal pin is determined to be short-circuit abnormal, it is determined otherwise to be normal. Can be detected.

4. The self-diagnosis method for a motor control system according to claim 1, wherein the first to fourth steps are executed every time the power of the system is reset. By executing at the time of reset, it is possible to detect a failure due to aging.

Further, a failure location such as a component constituting the system or a signal line is specified from the result of the self-diagnosis.
4. The self-diagnosis method for the motor control system according to any one of the above items 3 to 3, wherein a failure location can be specified, so that the cause analysis can be easily performed.

[0016]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a single-chip microcomputer, 2 is an LSI, 31 to 3X are input / output ports of the single-chip microcomputer 1, 41 to 4X are pull-up resistors,
The single-chip microcomputer 1 and the LSI 2 are connected by a bus pulled up by pull-up resistors 41 to 4X.

(Embodiment 1) In the normal operation, the input / output ports 31 to 3X are controlled by the built-in bus controller of the single-chip microcomputer 1, and the input / output functions are controlled by the ports connected to the bus. In many cases, settings can be made to general-purpose input / output ports. Here, the bus connection is performed using the switching function.
-3X I / O ports are set to general-purpose I / O ports,
A method of confirming the connection state with the SI2 will be described with reference to FIGS. 2 and 3.

First, the input / output ports 31 to 3X are set as output ports, and the first step (timing 100, step 200) of outputting the L potential is executed.

Thereafter, a second step (timing 101, switching input / output ports 31 to 3X to input ports) is performed.
Step 201) is executed, and the pull-up resistors 41 to 4
After a third step (step 202) of waiting for the delay time of the time constant of X, a fourth step (timing 102, step 203) of checking inputs of the input / output ports 31 to 3X is executed.

In the fourth step (step 203), if the pull-up resistors 41 to 4X are normally connected, the inputs of the input / output ports 31 to 3X are changed to the H potential by the pull-up resistors. So it can be judged normal,
If there is a disconnection or a short circuit with the L potential, the L potential remains and the abnormality can be detected.

In addition, if the detection is performed only once, there is a possibility of malfunction due to noise or the like. Therefore, it is possible to improve the detection accuracy by repeating the operations from the first step to the fourth step a plurality of times.

Although the first embodiment has been described as a group of 31 to 3X, it goes without saying that the same effect can be obtained even when the operation is performed one pin at a time. For example, since it can be specified as 31 of the input / output port, it is only necessary to check components and wiring patterns connected to the input / output port 31 at the time of analysis, and the analysis time can be greatly reduced.

The pull-up resistor can be similarly implemented by using a resistor built in the LSI.

Further, the abnormal portion may be displayed on a display device such as an LED, a liquid crystal, or a console of the motor control device, so that the development of a dedicated jig can be omitted.

(Embodiment 2) Next, a method for diagnosing the presence or absence of a short circuit will be described with reference to FIGS. 4 and 5.

Here, as an example, I / O ports 31, 32 and 33 which are physically adjacent are used, and
The method of diagnosing the presence or absence of the short circuit of No. 2 will be described.

First, the first step of setting the input / output ports 31, 32, 33 as output ports and outputting the L potential from the input / output port 31 and the H potential from the input / output ports 32, 33 (timing 300, step 400) Execute

Thereafter, the second step (timing 301, step 401) of switching the input / output port 32 to the input port is executed, and the third step (step 402) of waiting for the delay time of the time constant of the pull-up resistor 42 is performed. Then, the fourth step (timing 302, step 403) of checking the input of the input / output port 32 is executed. In the fourth step (step 403), if the input of the input / output port 32 is at the L potential,
1 and the input / output port 32 are determined to be short-circuited.

Then, the fourth step (step 40)
In 3), when the input of the input / output port 32 is at the H potential (normal state), the presence or absence of a short circuit with the input / output port 33 is further diagnosed as follows.

The first step (timing 303, step 404) of setting the input / output ports 31, 32, and 33 as output ports and then outputting the H potential from the input / output ports 31 and 32 and the L potential from the input / output port 33. ).

Thereafter, the second step (timing 304, step 405) of switching the input / output port 32 to the input port is executed, and the third step (step 406) of waiting for the delay time of the time constant of the pull-up resistor 42 is performed. Then, the fourth step (timing 305, step 406) of checking the input of the input / output port 32 is executed. In the fourth step, if the input of the input / output port 32 is at the L potential, the input / output port 33 and the input / output port 3
2 is determined to be a short circuit.

In the second embodiment, the single-chip microcomputer 1
Has been described as to whether or not there is a short circuit between adjacent input / output ports. However, the same can be done for adjacent pins and wiring patterns on the LSI 2.

[0034]

As is apparent from the above embodiment, according to the first to third aspects of the present invention, the state of the bus connection of the system can be controlled without providing a check land or I / O dedicated to the test. It is possible to make a diagnosis.

According to the fourth aspect of the present invention, a self-diagnosis is performed even when a failure occurs during a life cycle, and a malfunction of the system can be prevented.

Further, according to the fifth aspect of the present invention, it is possible to identify a faulty component or signal line from the result of the self-diagnosis, and to provide a quick service.

As described above, the function of self-diagnosing the connection state of the system without providing a check land or I / O dedicated for testing, the function of performing self-diagnosis even during the life cycle, and the parts and signal lines based on the self-diagnosis result Thus, it is possible to obtain a small, low-cost motor control system with high reliability, which has a function of specifying a failure location.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a bus connection in a motor control system according to a first embodiment of the present invention.

FIG. 2 is a timing chart for diagnosing a state of a bus connection in the first embodiment of the present invention.

FIG. 3 is a flowchart for diagnosing a state of a bus connection according to the first embodiment of the present invention;

FIG. 4 is a timing chart for diagnosing the presence or absence of a short circuit in a bus connection according to the second embodiment of the present invention;

FIG. 5 is a flowchart for diagnosing the presence or absence of a short circuit in a bus connection according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a bus connection in a conventional motor control system.

[Explanation of symbols]

 1 Single-chip microcomputer 2 LSI 31, 32, 33, 3X I / O port 41, 42, 43, 4X Pull-up resistor

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Claims (5)

[Claims] 1. A motor control system comprising a system in which one or more LSIs are bus-connected to a single-chip microcomputer, wherein a bus signal pin of the single-chip microcomputer is switched to an input / output port, and an L potential or H
A first step of outputting a potential, a second step of subsequently switching the input / output port to an input port, a third step of waiting for a time for the potential of the input / output port to stabilize, and a step of reading the potential of the input / output port. 4 steps,
A self-diagnosis method for a motor control system that performs a self-diagnosis from the result of the fourth step. 2. The motor control system according to claim 1, wherein in the fourth step, if the potential is specified by a pull-up resistor or a pull-down resistor, it is determined to be normal, and if not, it is determined to be abnormal. Diagnostic method. 3. The self-diagnosis method for a motor control system according to claim 1, wherein in the fourth step, if the potential of the adjacent signal pin is a short circuit, it is determined that the short circuit is abnormal, and if not, it is normal. 4. The self-diagnosis method for a motor control system according to claim 1, wherein the first to fourth steps are executed each time the power of the system is reset. 5. A system according to claim 1, wherein a failure location such as a component constituting the system or a signal line is specified based on a result of the self-diagnosis.
A self-diagnosis method for the motor control system according to any one of the preceding claims.