JPH0378666A - Bus noise testing apparatus - Google Patents

Abstract

PURPOSE:To prevent the forgetting to detach an effective value voltage measuring device or the destruction of said device by automatically connecting the effective value voltage measuring device to a bus according to the state of a noise generator when the noise test prescribed on the basis of an MIL standard is performed. CONSTITUTION:A noise generating voltage measuring part is constituted of a noise generator 10 generating noise, command and state signals 13, 14, 15, a noise level effective value voltage measuring device 11 and a signal change- over part 12 connecting the measuring device 11 to a bus 2 and separating the same from said bus 2 on the basis of a -OE signal 16. At first, a command level is matched with a prescribed value in a noise testing process but, at this time, a -CE signal 14 becomes L and, therefore, the -OE signal 16 becomes H and the change-over part 12 separates the measuring part 11 from the bus 2. Next, when a noise level is matched with the prescribed value, a -NE signal becomes L and, therefore, the -OE signal also becomes L. Therefore, the change- over part 12 connects the measuring device 11 to the bus 2. During the noise test, a -TE signal becomes L and the -OE signal becomes H and the measuring device 11 is separated from the bus 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a test device that can automatically measure the effective value voltage of the noise level when performing a noise test specified by MIL-HDBK-1553B. be.

[Conventional technology]

FIG. 3 shows the configuration of a conventional noise testing device. As shown in the figure, (1) is MIL-STD-1553B
(2) is a bus simulation unit that monitors serial data transfer according to the communication standard defined in MIL-STD-155.
The bus cable defined in 3B, (3) is the TOΩ terminator j for terminating the bus (47 is the bus connection part for connecting the bus cable, (5) is the device under test for noise testing, ( 6) is white Gaussian noise specified by MIL-HDBK-1553B and MIL-STD-1
(7) is the effective value voltage measurement unit that is connected to the bus cable (2) only when measuring the effective value voltage of the noise level; (8) is the (6) ) consists of a waveform observation section for measuring the level of commands transferred from the noise generation section. When testing in such a configuration, first connect only the waveform observation section (8) to the bus cable (2),
The noise generator (6)) transfers the command and adjusts the command voltage level to the specified value. When the command voltage level matches the specified value, the noise generating section (6) stops transmitting the command and the waveform observing section (8) is removed from the bus cable. Next, the noise generating section generates noise, connects the effective voltage measuring section (71) to the bus cable, and adjusts the noise effective voltage level to the specified value.The effective voltage measuring section adjusts the noise effective voltage level to the specified value. (7) is removed from the noise generating unit (6). At the command pressure level set in the previous section, a command is transferred at the same time as the noise and the noise test is started. At this time, the bus simulation unit (1) transfers the command on the bus. Monitor and determine whether a specified number of commands are recognized by the test object (5).

[Problem to be solved by the invention]

Conventional noise test equipment is configured in more than one way, so when performing a noise test, you have to disconnect the device to which the effective value voltage measurement section is connected, which is time-consuming, and you may forget to disconnect it. Just in case you want to test.

There are problems such as destroying the effective value voltage measuring section and not being able to perform accurate tests.

This invention was made to solve the above-mentioned problems, and provides a noise testing device that automatically connects and disconnects the effective value voltage measuring section depending on the state of the noise generating section. The purpose is to

[Means to solve the problem]

The noise testing device according to the present invention has a signal switching section that allows the noise generating section to output a signal depending on its own state, and connects and disconnects the effective value voltage measuring section and the bus according to the signal, This allows the effective value voltage measuring section to be automatically disconnected from the bus.

[Effect]

The noise test device according to the present invention includes a noise generator that can generate a signal based on the test condition, a signal switching section that connects and disconnects the signal from the bus, and an effective voltage measuring section that automatically measures the noise. It is automatically connected to and disconnected from the bus, and some of the noise test operations are automated.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
In the figure, (1) to (8) are (
8) is a noise-generating voltage measuring section that generates noise and commands and can automatically connect and disconnect the effective value voltage measuring device from the bus. FIG. 2 is a configuration diagram as an example of the noise generation voltage measuring section of FIG. 1. (2) is the same as the above conventional technology, +11 is noise and command, status signal (03
+14) αS), a noise generating section that generates (111
is an rms voltage measuring device that measures the noise level as an rms value,
a3 is a signal switching unit that disconnects and disconnects the effective value voltage measuring instrument from the OE multiplied signal-based bus, and αj is 'L when performing a noise test.
” TK double signal Q4) is “L” when outputting the command.
There is the OK multiplied signal αS which becomes "L" when noise is output, and the NE multiplied signal ae which becomes "L" when the effective value voltage measuring section is connected to the bus.

In such a configuration, operations (1) to (8) are similar to those of the prior art described above. During the noise test, the Ozu command level is adjusted to the specified value, but at this time the cz4B No.a
4 is L", so the OE double signal is "H") signal switching section (L
2 turns off the effective value voltage measuring section αυ and the bus (2). Next, when adjusting the noise level to the specified value, the NE signal □□□ becomes L11j) The OK signal ae also becomes "L". Therefore, the signal switching unit (in Lz, the effective value voltage measuring device a)
9 to the bus (2). Also, during the noise test, the TE multiplied signal L"01 signal is "H", so the effective value voltage measuring device is disconnected from the bus at the signal switching section.

〔Effect of the invention〕

As described above, in the noise test device according to the present invention, since the connection of the effective value voltage measuring device to the 1553B bus is automatically performed depending on the state of the noise generator, the troublesome effective value voltage measurement device is connected to the 1553B bus. It is necessary to connect manually.
Furthermore, it is possible to eliminate test failures and damage to the effective value voltage measuring device due to forgetting to remove the container.

[Brief explanation of drawings]

1 and 2 are block diagrams showing a noise test device according to an embodiment of the present invention, and FIG. 3 is a block diagram of a conventional noise test device. In the figure, (1) is the bus simulation part, (2)
is the bus, (3) is the bus connection, (4) is the bus terminator, (
5) is the test object, (6) is the noise generator, (71 is the effective voltage measurement unit, (8) is the waveform observation unit, (91 is the noise generation voltage measurement unit, αυ is the noise generator, and αD is the effective Value voltage measuring device, Q3 is signal switching unit, (13 is TE multiplied signal
aa is the CFX signal, α is the NK times signal (IO is 011:
It's a signal. In Figure 9, the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] A bus simulator that can monitor serial data transfer and MIL-STD-15 for terminating the bus according to the communication standard defined by MIL-STD-1553B.
A bus connection section defined by MIL-STD-1553B for connecting a bus terminator defined by 53B and a bus cable, and a function to perform serial data transfer according to the communication standard defined by MIL-STD-1553B. , M.I.
A noise generation voltage measurement unit that has the function of generating white Gaussian noise specified by L-HDBK-1553B and the function of measuring the noise level with an effective value voltage only when white Gaussian noise is generated. ,
A bus noise test device comprising: a waveform observation section having a function of differentially measuring the voltage level of serial data on a bus; and a device under test for performing a noise test.