JP2560558B2 - Exclusive control method when package is erroneously mounted - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exclusive control method when a package is erroneously mounted, and particularly in a plurality of packages which are mounted on one unit and whose input terminals or output terminals are connected by a backboard of this unit. At the same time 1
The present invention relates to an exclusive control method that allows implementation of only one package.

[0002]

2. Description of the Related Art As a conventional exclusive control method at the time of package erroneous mounting, a method of changing the connector type for each package so that erroneous mounting cannot be performed, or unifying the power supply terminals of the package so that minimum failure does not occur The method of doing was adopted.

[0003]

In the conventional exclusive control method at the time of erroneous package mounting, when the connector type is changed for each package, different connectors must be prepared for each package type, and the number of connector types increases. In addition, there is a problem that it is not applicable when there is a condition that the connector must be the same type. In addition, there is a problem that the phenomenon of signal disconnection due to erroneous mounting cannot be solved by the method of unifying the power terminals of the package.

[0004]

The exclusive control method for erroneous packaging of a package according to the present invention is a plurality of packages which are mounted on one unit and whose input terminals or output terminals are connected by a backboard of the unit. Means for recognizing a mounting state of a package other than the own package in the unit in the exclusive control formula of the package, and at least one of the other packages is already in the unit when the own package is mounted in the unit. Each of the plurality of packages is provided with means for setting the input terminal or the output terminal of the own package to high impedance when it is recognized that the package is mounted.

[0005]

The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. The first package 11 and the second package 21 are input pull-up by pull-up resistors 13 and 23, respectively, and outputs are tri-state buffers 14 and 2, respectively.
4 has the inverters 12 and 22 connected to the control terminal of the fourth package, and the mounting state signal 33 of the first package which is the output of the inverter 12 and the second which is the output of the inverter 22
The package mounting status signal 32 of the other package is cleared on the backboard 31 and
It is connected to 12 inputs. The output 34 of the first package and the output 35 of the second package are wired or connected on the backboard 31.

Next, the operation will be described.

In a normal operating state, the first package 1
The first and second packages 21 are not mounted at the same time.
Now, consider a state in which only the first package 11 is mounted and the second package 21 is not mounted. At this time, the mounting state signal 32 of the second package becomes open,
The input of the inverter 12 of the first package 11 is "H"
The output of the inverter 12 becomes "L" level, the tri-state buffer 14 is enabled, the output 34 of the first package is made active, and the mounting state signal 33 of the first package is set to "L". L "
Level.

When the second package 21 is erroneously mounted in this state, the input of the inverter 22 is at "L" level, the output of the inverter 22 is at "H" level, and the output of the tri-state buffer 24 is set at high level. The impedance is set and the mounting state signal 32 of the second package is set to the “H” level to enter the stable state. By the operation principle described above, it is possible to prevent the output 34 of the first package previously mounted from being disturbed.

Even when the outputs of three or more packages are wired or connected on the backboard 31, the same operation as described above is performed and only the first package mounted becomes effective.

Further, although the case where the package output is wired-OR is described in this embodiment, it is obvious that the same effect can be obtained even when the package input is wired-OR.

[0012]

As described above, according to the present invention, a plurality of packages mounted on one unit and having input terminals or output terminals connected to each other on a backboard of the unit are mounted on other packages. It has a means to recognize the state and a means to make the input terminal or the output terminal of the own package high impedance when it recognizes that another package is already mounted in the unit at the time of mounting the own package. Therefore, even if the package is erroneously mounted, it is possible to prevent the already mounted input terminal or output terminal from disturbing the input or output of another wired-OR package.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

[Explanation of symbols]

 11 First Package 12,22 Inverter 13,23 Pull-up Resistor 14,24 Tri-State Buffer 21 Second Package 31 Backboard 32 Second Package Mounting Status Signal 33 First Package Mounting Status Signal 34 First Package output 35 Output of second package

Claims (1)

(57) [Claims] 1. An exclusive control type of a plurality of packages mounted on one unit and having their input terminals or output terminals connected to each other on a backboard of the unit, wherein Means for recognizing the mounting state in the unit, and the input of the own package when recognizing that at least one of the other packages is already mounted in the unit when the own package is mounted in the unit. An exclusive control method when a package is erroneously mounted, wherein each of the plurality of packages is provided with a means for setting a terminal or the output terminal to a high impedance.