JPH11249766A - Power supply voltage abnormality detector for multiple boards - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a power supply voltage deviates from a predetermined range for driving a substrate in a circuit device composed of many substrates,
A maintenance function is provided for indicating a power supply voltage abnormality on a board-by-board basis, automatically holding the power supply voltage value, reading stored data, and verifying the power supply voltage abnormality on a board-by-board basis. SOLUTION: A circuit device having a plurality of boards is provided with monitoring means for monitoring a power supply voltage of the boards, alarm means for generating an alarm when the power supply voltage exceeds a specified range, and monitoring of the power supply voltages from all the boards. An identification means is provided for receiving data and identifying which board has a power supply voltage abnormality when an error occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can detect the occurrence of a voltage abnormality for each substrate when a DC power supply voltage supplied for driving the substrate is out of a certain range, even if the substrate comprises a large number of substrates. The abnormal voltage value can be recorded and read out, and furthermore, by notifying the detection result by character display and buzzer,
The present invention relates to a power supply voltage abnormality detecting device in a circuit device having a large number of substrates for improving the maintenance efficiency of each substrate.

[0002]

2. Description of the Related Art In a main board, when a supplied power supply voltage deviates from a predetermined range for driving the board, the voltage value is detected and only a retreat operation is performed when the power supply voltage is abnormal. However, when the device is composed of a large number of boards, the power supply voltage on each board varies due to the voltage drop from the power supply cable, etc., and various errors occur due to malfunction due to abnormal power supply voltage on each board. It is possible. For this reason, not only detection of the power supply voltage abnormality of the main board but also more detailed verification that can clearly determine whether an error has occurred due to the power supply voltage abnormality in all the boards is required. Further, when a power supply voltage abnormality is detected, the power supply voltage value is automatically held so that the power supply voltage value can be read as data for each board, and it is necessary to improve maintainability to verify and warn the abnormal voltage value.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit device having a large number of substrates, and when a power supply voltage is out of a predetermined range for driving the substrates, a power supply voltage abnormality is indicated for each substrate. In addition, a maintenance function that automatically holds the power supply voltage value, reads out the stored data, and verifies whether the cause of the power supply voltage abnormality or malfunction due to the power supply voltage abnormality in detail for each board is provided. It is.

[0004]

SUMMARY OF THE INVENTION In a circuit device having a plurality of substrates driven by a certain range of power supply voltage, monitoring means for monitoring the power supply voltage of the substrate, and alarming when the power supply voltage exceeds a specified range. In addition to providing alarm means for generating, receiving monitoring data of power supply voltage from all boards,
This is achieved by a power supply voltage abnormality detection device, comprising: identification means for identifying which substrate has caused a power supply voltage abnormality when an error has occurred.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A circuit A is a monitoring means comprising a power supply voltage check circuit mounted on each board and a voltage holding means comprising a data holding circuit. The resistors 1 to 4 define upper and lower thresholds of an arbitrary voltage to be monitored, and the comparators 5 and 6 as monitoring means monitor whether the power supply voltage is within a specified voltage range. When the power supply voltage is out of the specified range, the output signal of one of the comparators 5 and 6 is inverted, and the output signal of the OR circuit 7 to which the output signal is input is also inverted. The inverted output signal of the OR circuit 7 serves as a trigger, inverts the output signal of the flip-flop circuit 10, is held as a signal indicating the substrate on which the voltage abnormality has occurred, and is input to the I / O 14. At the same time, the OR circuit 7
Using the inverted output signal as a trigger, the power supply voltage value converted into digital data by the A / D converter 9 is automatically held by the latch circuit 10 as voltage holding means. The circuit A automatically performs a series of operations on each substrate when the power supply voltage is out of the range of the specified value.

Circuit B is a power supply voltage check and data holding circuit mounted on the main board. Basic operation is circuit A
Is the same as However, since the power supply voltage of the board on which the main CPU 11 is mounted is monitored, if an abnormality occurs in the power supply voltage, the operation of the board cannot be guaranteed, so that the malfunction of the board is prevented. Is input to the non-mascarable interrupt signal of the main CPU 11. Main CPU 11
When the non-mascarable interrupt signal is input,
In order to verify the cause, the data of the I / O 14 is read, and it is checked whether a voltage abnormality has occurred in the main board. If a voltage abnormality has occurred, an abnormal voltage value is read from the latch circuit 10 and the decoder circuit 1
6 to select and write the EEPROM 17. By this processing, even if the power supply voltage abnormality is a power failure, the abnormal voltage value can be held and analyzed by reading it out later.

The circuit C is a circuit for identifying a board on which a power supply voltage abnormality has occurred in the main board, reading an abnormal voltage value, and displaying a warning. The main CPU 11 is an identification means for selecting the I / O 14 by the decoder circuit 12, reading which bit data has changed, and identifying which board has a voltage abnormality. Based on the identification result, the abnormal voltage value is read from the latch circuit 10 of the substrate on which the voltage abnormality has occurred by the data bus connection bus transceiver 13 which is a reading means, and the name of the abnormal substrate and the occurrence of the abnormal voltage value are displayed in characters and a buzzer. The alarm circuit 15 which is an alarm means having a function notifies the user by character display and a buzzer.

When a power supply voltage abnormality occurs in the main board and is detected, an EEPR serving as a power failure voltage holding means is used.
After writing the abnormal voltage value to the OM 17, a save operation such as data protection for preventing a malfunction of the substrate is performed.

[0009] Each bit of the I / O 14 is allocated in advance to each board, and by reading which bit is inverted, it is possible to find out on which board the power supply voltage abnormality has occurred.

Make it possible.

According to the present invention, in an apparatus composed of a large number of substrates, the presence or absence of a substrate having a power supply voltage abnormality in an error detection process is searched, and the power supply voltage value is read and data is compared. Accordingly, it is possible to verify and warn whether a power supply voltage abnormality has occurred on a board-by-board basis, and it is possible to enhance the maintenance effect in more detail.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

[Explanation of symbols]

Reference numerals 1 to 4 are power supply voltage dividing resistors, 5 and 6 are power supply voltage abnormality detection comparators, 7 is an OR circuit, 8 is a flip-flop circuit, and 9 is an A for digital data conversion of analog voltage.
A / D converter, 10 a holding circuit for a power supply voltage value converted into digital data, 11 a main CPU, 12 a decoder circuit for I / O selection, 13 a bus transceiver for data bus connection, 14 an I / O circuit, Reference numeral 15 denotes an alarm circuit having a character display circuit and a buzzer circuit, 16 denotes an EEPROM select decoder circuit, and 17 denotes an EEPROM.

Claims (3)

[Claims] 1. A circuit device having a plurality of substrates driven by a power supply voltage within a predetermined range, a monitoring means for monitoring the power supply voltage of the substrate, and an alarm for generating an alarm when the power supply voltage exceeds a specified range. A power supply voltage abnormality detection device, comprising: a power supply voltage monitoring unit that receives power supply voltage monitoring data from all of the substrates and identifies which substrate has a power supply voltage abnormality when an error occurs. 2. The apparatus according to claim 1, further comprising: holding means for automatically holding a power supply voltage value when a power supply voltage abnormality occurs for each substrate; and reading means for reading out the held power supply voltage value. A power supply voltage abnormality detection device as described in the above. 3. The power supply voltage abnormality detection device according to claim 2, further comprising a holding unit that holds an abnormal power supply voltage value even at the time of a power failure, and reads and analyzes the power supply voltage after power recovery.