SU690665A1 - Device for majority selection of signals - Google Patents

Description

I

The invention relates to the field of computer technology and automation and can be used in the design of computing devices with redundancy.

There are known devices for the majority selection of input signals |, {2 |, containing AND elements and OR elements. The disadvantages of such devices are that they do not provide the possibility of transition from a permanent reservation to a reservation by substitution, as well as the control of the health of the constituent elements; com without additional control devices.

The closest technical solution to the invention is a device 3 for a major signal choice, which contains I-NE elements and inverters in three channels: However, such a device has a large number of communication lines between the channels, which reduces the reliability of operation and complicates the device with a large number of redundant nodes and the implementation of backup channels in the form of an independent design.

The aim of the invention is to simplify the device and increase its reliability, in

in particular, by reducing the number of communication lines between channels.

This goal is achieved by the fact that the proposed device contains a driver in each channel, the output of which is connected via the first inverter to the first inputs of the first and second AND elements of the given channel, and through the second inverter to the second input of the first AND elements of the previous channel. The second input of the second NAND element of each channel is connected via the third inverter to the output of the first NAND element of this channel and the output of the second NAND element of the previous channel.

The drawing shows a block diagram of the device.

The device contains the first and second elements AND-NOT 1-6, implementing a two-step logic function AND-ILINE in each channel (majority block) 7-9, the first, second and third inverters 10-18 and drivers 19-21, providing matching the input resistances of inverters with output impedance signal sources.

Inputs 22-24 devices and outputs 25-30 are used to connect the previous and subsequent redundant devices.

The device works as follows.

In the ERROR of the PSTNDB reservation, the signals at the outputs of the device take on values that coincide with the value of the signal on most inputs, i.e. the device performs the majority selection of input redundant signals. In this case, at all outputs 25, 27 and 29 or 26, 28 and 30, a signal is provided in accordance with the majority function MIS-Mi7 MM All. AIJ + AIZ- AZH + Agz Aj4i, or Mie MZS Mjo Agg At5 Atj + Asch All + Agz Ai4 | respectively,

where Mas-, Mrs, MI ... Mjo are the output signals;

All, AIJ and AG1 (- input signals.

Each backup channel of the device with the power supply volume number from the other two functions as a repeater or inverter. Thus, when the power supply is supplied only to the major block 7, output 25 will have a signal corresponding to the MIS function Agg Ajz, and output 26 will have a signal corresponding to the function MgeAc Aq.

At the same time, it is possible to draw a conclusion on the health of the imaging device 19, the inverter 12, the AND-NOT elements G, 2 and the inverters 10, 11. Indeed, if there is a malfunction in any of these elements, there are no signals at the outputs 26, 26 or 27. For example, in case of malfunction of the former 19 or inverter 12, the signal at all outputs 25, 26 and 27 is absent, and when the inverter fails 11 (failure O-1) there is no signal at output 26, with a different kind of inverter failure 11 (failure 1-0 a) signal is absent at the outputs 26 and 27; in case of malfunction of the NAND 2 element, there is no signal at output 27, etc.

In the general case, in case of failure of an element of any channel, it is possible to determine which element failed by supplying power to each channel separately, and then to channel pairs, and determine the failure element and the type of failure by the nature of the output signals at outputs 25-30. For example, in case of failure of any element of the channel of the majority block 7, the table below can be used.

 Indeed, if an AND-NOT 2 element failed, then supplying power only to the channel (majority unit) 7, and making sure that the outputs 25 and 26 have a repetition and inversion of the signal from output 22, respectively, and at output 27 the signal is constant - O or 1, it can be concluded that an AND-NOT 2 element failed, and if there is an O level at output 27 - the failure is 1-O, and if there is a 1, the failure is O-1.

If inverter 19 fails, it is necessary to energize channels 7 and 9 (majority units) in order to determine the presence and type of failure according to the outputs 25, 26, 27, 29 and 30 (see table).

0 Similar tables can be made to check the health of the channels (majority units) 8 and 9.

The technical and economic effect of the application of the invention is that the device provides at its outputs a major sample of input signals, protection from single failures of any element, the possibility of switching from substitution reservation to permanent reservation and back by switching the channel power and the ability to check the health of all elements when using 4 instead of 5 communication lines between each channel and two others, the device allows to eliminate interference on communication lines when working in the reservation mode an replacement (i.e., when power is cut off from two channels), since in the channel to which power is supplied, only one of the inverters (10, 13 or 16) is connected to the input with a de-energized link, but this line is connected

to shaper output with low output impedance. In this case, interference of type O-1 for positive logic or 1-O for negative logic at the input of this inverter is excluded.

Claims (3)

1. US Patent No. 3524073, cl. 307-24, published. 1970. 2. Avto skba certificate of the USSR No. 247622, cl. G 06 E 11/00, 1967. 3. USSR author's certificate No. 240776, class, G 06 E 11/00, 1975.