JP2605597Y2 - Self-diagnosis circuit for analog output channels - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-diagnosis circuit for an analog output channel.

[0002]

2. Description of the Related Art Electronic and electrical devices mounted on aircraft are required to be small, light, and highly reliable like other devices.
In order to ensure high reliability, a self-diagnosis function (self-diagnosis circuit, BIT circuit) is provided. FIG. 2 shows an example of an electronic system having such a self-diagnosis function. In the figure, 10 is a main unit (CPU), 11 is a data bus, 12 _{1 to} 12 _n are D / A converters, 13 _{1 to} 13
_n is an amplifier. 20 is an analog switch, 21 is A
/ D converter.

[0003] The main unit (CPU) 10 is a digital signal D / A converter through a data bus 11 12 ₁ to 12 _n
, And set them. D / A converter 1
2 ₁ to 12 _n is transmitted to the amplifier 13 ₁ to 13 _n convert the digital data into analog signals. Analog switch 20 sequentially selects the amplifier 13 ₁ to 13 _n and inputs the output to the A / D converter 21. The A / D converter 21 converts an analog input into a digital signal and returns it to the main unit (CPU) 10. The main device (CPU) 10
Run the test program, properly signal from the amplifier 13 ₁ to 13 _n from the output of the A / D converter 21 to diagnose whether or not it is transmitted.

[0004]

[Devised Problem to be Solved] In this self-diagnosis circuit, since inputs the output sequentially selects amplifier 13 ₁ to 13 _n in the analog switch 20 to the A / D converter 21, the analog output channels increases, In addition to the time required for diagnosis (check) being prolonged, the A / D converter 21 becomes large-scale and expensive when high precision is required. There are many problems for mounting. The present invention has been made to solve this problem, and it is possible to perform a highly accurate diagnosis using a small, lightweight, and inexpensive device. An object of the present invention is to provide a self-diagnosis circuit for an analog output channel.

[0005]

[Means for Solving the Problems] The present invention achieves the above purpose
To do,Claim 1 states that the electronic and equipment mounted on the aircraft
In the device, the electronic / equipment device isTest program
Run the programA main unit and a plurality of data output by the main unit.
Digital data to the corresponding analog signal
Multiple analog output channels to output analog signals
A circuit provided in an apparatus having a channel,
Captures analog output signals output from each channel
Obtain the sum of the levels of the analog output signal
Judgment of match / mismatch between circuit and total value and set value
TimesDown the roadThe main unit outputs the output of the judgment circuit.
Capture the above analog output channelOne of
Is there goodnoOrToCollectivelyNavigation characterized by judgment
Analog output channel self-diagnosis circuit for airborne installation
is there.

[0006] In claim 2, the main unit, appropriate analog output signal <br/> analog output channels of the whole hand and all
2. The program according to claim 1, wherein the sum is programmed to match the set value when
Self-diagnosis circuit of analog output channel for aircraft
It is.

[0007]

[Function] In the present invention, the electronic and equipment devices mounted on the aircraft
Output from the main unit that executes the test program
Converts multiple digital data into corresponding analog signals.
Replace. Then, from multiple analog output channels,
Takes in the analog output signal output Re respectively calculates the total level sum thereof <br/>, it determines coincidence-mismatch between the sum and the set value. The main device I write takes this decision output,
Is any of the above analog output channels defective?
It is determined in a lump whether it is or not.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, R _{1 to} R _n are resistors, 30 is an operational amplifier (feedback resistor R _f ), and 31 is a comparator. The analog outputs of the amplifiers 13 _{1 to} 13 _n are respectively connected to resistors R _1.
It is taken through to R _n, of the operational amplifier 30 is converted into a voltage value V ₁ ~V _n - is input to the terminal. V _ref is a reference voltage. The output of the operational amplifier 30 is input to the comparator 31, and the main device (CPU) 10 reads the output of the comparator 31.

In this configuration, the amplifiers 13 _{1 to} 13
_If all analog outputs from _n are correct, V ₁
All sum of ~V _n is Yes set to a predetermined value V _0, also is set to V _ref such that V ₀ = V _ref.

Therefore, _if the analog outputs from the amplifiers 13 _{1 to} 13 _n are all appropriate, the output of the operational amplifier 30 is 0, and if the output value of the comparator 31 is a value other than 0, device (CPU) 10 is not appropriate any of the analog output from the amplifier 13 ₁ to 13 _n is, the amplifier 13 ₁ to 13 _n is either an analog output channels including each it is diagnosed as defective.

The comparator 31 determines whether the output of the operational amplifier 30 is 0 and outputs an "H" level or "L" level signal, so that the main unit 10 directly takes in the output of the comparator 31. be able to.

[0013] The main unit 10, the analog output signal of the analog output channels of the entire hand are all appropriate place
In this case, programming is performed so that the above total sum matches the above set value.

As described above, in this embodiment, the amplifier 13 ₁
Collectively check the analog output from the ~13 _n. Further, since the main device 10 is merely given as a signal whether or not the output of the operational amplifier 30 is 0, diagnosis can be quickly and accurately performed using inexpensive circuit elements,
It is very suitable for use in aircrafts that require more accurate and quick diagnosis.

[0015]

[Effects of the Invention] As described above, the present invention provides a test pro
Multiple digital data output by the master
Multiple analog outputs of analog signals converted from data
Respectively output from the channel, these analog output signals
To determine the match or mismatch between the level sum when the set value of the item,
Based on this determination, the main unit determines whether the analog output channel
Since it is determined in a lump whether or not the deviation or in a defective, on even increasing analog output number of channels less time extremely time required for diagnosis, diagnosis, or the sum is out of the set value Because it is simple or not,
High-precision diagnosis can be performed using a lightweight and inexpensive circuit element.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a conventional diagnostic circuit.

[Explanation of symbols]

Reference Signs List 10 Main unit (CPU) 12 _{1 to} 12 _n D / A converter 13 _{1 to} 13 _n amplifier 30 Operational amplifier 31 Comparator R _{1 to} R _n resistance

Claims (2)

(57) [Scope of request for utility model registration] An electronic / equipment mounted on an aircraft executes the test program.
That Master and, a circuit provided with the analog signal into a plurality of digital data into a corresponding analog signal and outputs the main device to the device comprising a plurality of analog output channels for outputting respectively, each channel A circuit for taking in an analog output signal output from the controller and obtaining a level sum of the taken-in analog output signal; and a circuit for judging whether or not the sum and the set value match each other. Capture output and one of the analog output channels is defective
Self-diagnosis circuit of the analog output channels for aircraft, characterized in that it is determined whether the collectively. 2. The apparatus according to claim 1, wherein the main unit is programmed so that the sum when all analog output signals of all the analog output channels are proper is equal to the set value. Self-diagnosis circuit of analog output channel for aircraft.