SU1228140A1 - Displaying device - Google Patents

Abstract

The invention relates to automation and computing and can be used to enter information on segment indicators. The purpose of the invention is to increase reliability. The goal is achieved by introducing into the device a block of limiting elements, an analog-code converter, a second switch, a counter, and a series-connected delay element, a counter, and a modulo two. The introduction of these elements leads to the fact that if an element of the indication element is broken, connecting or disconnecting this element does not cause a change in the current through the resistors of the limiting element block, as a result of which the further change in the counter state stops and the indicator remains in the state where the fault was detected. 1 il.

Description

The invention relates to automation and computing and can be applied, in particular, to display information on segment indicators operating in multiplexing mode.

The inventive principle is to increase the reliability of the device.

The drawing shows a block diagram of the device.

The device contains a pulse generator 1, a polling unit 2, a key block 3, an indication block 4, counting decades 5, a first switch 6, a decoder 7, an OR element 8, a second switch 9, a trigger 10, a counter 11, a block of 12 limiting elements, an adder 13 modulo two, delay element 14, converter 15 analog-code.

The device works as follows.

The clock pulses from the generator 1 are fed through the switch 9 to the polling unit 2, which sequentially through the switch 6 connects the outputs of counting decades 5 to the decoder 7. The signals from the outputs of the decoder 7 turn on the indicator elements (for example, segments) of the display unit 4. Simultaneously from the polling unit 2 through the unit 3 of keys, the block 12 of limiting elements to the control inputs of the block 4 of the indication receives switching on pulses. As a result, symbols corresponding to the information stored in the counting decades 5 are displayed.

When connected to display unit 4 of the i-th decade, a signal appears at the i-th input of the 3 key block, which from the i-ro output of the 3 key block via the corresponding resistor of the block 12 goes to the control input of the i-display indicator of the display unit.

Since at least one element (segment) of the indicator corresponds to any displayed symbol, the control signal circuit is closed and current is flowing through the resistor of block 12, creating a certain voltage drop relative to the output of the 3 key block. This voltage drop through block 15 is transmitted to the element OR 8. The output state of the element OR 8 does not change in the process of displaying information stored in the counting decades 5.

When an external signal arrives at the device, testing the trigger 10 is set to one, the polling unit 2 and the counter 11 is set to the initial state. The polling unit 2 generates a control signal for turning on the first indicator, and a signal from the output of the trigger 10 through the switch 6 bits

The decoder 7 connects the outputs of the counter 11 and prevents the passage of pulses from the generator 1 through the switch 9 to the input of the polling unit 2. Code for the initial installation of the counter 11

5 has no correspondence in the alphabet of the decoder 7, and no signal for switching on the display element is generated at any of the outputs of the latter. The indicator control signal circuit is open-circuited, the voltage does not drop across the resistor of block 12, and a change in state occurs at the output of the OR 8 element, which causes the holder to form 14 of the holder and the adder 13 modulo two pulses. This pulse arrives at the counting input of the counter 11 and transfers it to the second state. This state corresponds to the shape (j is the decrypter 7 of the turn-on signal of the first elements of the indicators of block 4.

The indicator control circuit closes, WHAT causes a voltage drop across the resistor of the block 12 and a signal change at the output of the element OR 8. At the output of the modulator 13 modulo two, a second counting pulse is formed, switching the counter 11 to the third state. To all (2n-1) -th (odd) states of counter 11 there is no match in the alphabet of the decoder 7, to each 2-th (even) state of counter 11 there corresponds a signal at the output of the decoder 7 connected to the nth display elements of unit 4 When the device is working properly, a change in the state of the counter 11 leads to a change in the output state of the element OR 8, which causes the counting pulse to appear at the input of the counter 11. After checking the last display element of the first indicator by the counter 11, a signal is generated that passes through the switch 9 to entrance block 2 of the survey and switches it to the next state. After checking the last element of the last indicator with a signal from the output of the block.

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When 2 polls are reset, a 1U trigger is reset and the device resumes indication of the states of the counting decades 5.

Violation of the circuit of any indication element (open or short circuit) causes the connection or disconnection of this element does not cause a change in the current through the resistors of the block 12, as a result of which the further change in the state of the counter 11 stops. The indicator remains in the state., In which a fault is detected — not a single element is lit or a non-equal one is lit.

The duration of the monitoring is determined by the time t zade; the switching intervals of the elements of the device are equal to T a-b-g, where a is the number of bits of the display unit 4; b - the number of elements of one indicator.

The value of T in modern devices does not exceed 10 -10 s. Therefore, the entire control process at a b 100 takes 10 s and a change in the state of the indicators during this period does not affect the perception of information by the operator.

Claims (1)

Invention Formula A display device containing counting decades, the outputs of which are connected to the inputs of the group of the first switch, the outputs of which are connected to the decoder, the outputs of which are connected to the information inputs 228140 the display unit, the key block, whose inputs are connected to the output of the polling unit, the first output of which is connected to the first input of the first switch, the OR element, a trigger and a pulse generator, characterized in that, in order to increase the reliability of the device, block of limiting elements, 10 analog-code converter, second switch, counter and serially connected delay element and modulo two adder, the output of which is connected to the first input of the counter t5 of the pickup, the first output of which is connected to the second input of the first The switch, the third input of which is connected to the trigger output and the first input of the second switch, the second input of which is connected to the output of the pulse generator, and the third input is connected to the second output of the counter, the output of the second switch is connected to the first input of the polling unit, the second output of which is connected to the first the trigger input, the inputs of the key block are connected to the inputs of the block of restrictive elements, the outputs of which are connected to the control inputs of the display unit and the analog-code converter inputs whose outputs are connected to input and output With the signals of the OR element, the output of which is connected to the input of the delay element and the second input of the modulo two adder, the second input of the counter is connected to the second inputs of the trigger and the interrogator and is the device input. 20 25 thirty 35 VNIIPI Order 2290/51 Random polygons pr-tie, Uzhgorod, st. Project, 4 Circulation 455 Subscription