CN115390494A - A high and low level state automatic acquisition device under small current - Google Patents

Abstract

The invention relates to an automatic acquisition device for high and low level states under low current, and belongs to the technical field of data acquisition. The invention can realize the CPU acquisition of high and low switching values under the low current state, and when the external switching value of the computer is in a changing state, the device can automatically identify without manual setting.

Description

A high and low level state automatic acquisition device under small current

technical field

The invention belongs to the technical field of data acquisition, and in particular relates to an automatic acquisition device for high and low level states under low current.

Background technique

In the field of computer control, the CPU processor usually needs to rely on the state acquisition circuit when collecting the state of the external switch of the computer. When the high and low levels of the external switching value are different, the settings of the state acquisition circuit will also be different, as shown in Figure 1a and Figure 1b. Although it can be solved by manual jumper, when the CPU processor needs to collect and calculate the state of multi-bit switches, the manual jumper work is bound to be complicated, and it also increases the cost of jumper devices, which is not conducive to the miniaturization design of computer modules; When the external switch position of the computer is in a changing state, the manual jumper method cannot solve it, as shown in Figure 2.

As shown in Figure 1a and Figure 1b, when the status bits of the external switching values of the computer are different, the chip pins corresponding to the switching values in the acquisition circuit are different. As shown in Figure 2, the switching quantity acquisition circuit is designed by jumper. When the switching value is a high-level status bit, jump the wire to the diode positive pin of the acquisition circuit, and when the switching value is a low-level status bit, jump the wire to the diode negative pin of the acquisition circuit.

To sum up, the traditional computer external switching value acquisition circuit cannot automatically collect high and low level levels, and increases the overhead of jumper devices, which is not conducive to the miniaturization design of computer modules.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is: how to design an automatic acquisition device for high and low level states under low current, which can identify and collect the external switch state of the computer without manual setting.

(2) Technical solution

In order to solve the above-mentioned technical problems, the present invention provides a high-low level state automatic acquisition device under a small current, which includes two parts, a relay and an acquisition circuit; the relay is used to realize the switching control of the high and low level state of the external switch of the computer; The acquisition circuit is used for converting the state of the external switch quantity of the computer into the identification state bit of the CPU processor.

Preferably, the relay is equipped with six sets of changeover contacts, which are responsible for the high and low state switching control of the 2-bit switching value, and the acquisition circuit is responsible for the state transition identification of the 4-bit switching value, including four photocouplers and four current-limiting resistors , The input current of the acquisition circuit is 5-20mA.

Preferably, the negative pole of the coil of the relay is connected to the power ground of the computer, and the positive pole of the coil is connected to the positive pole of the switching command sent by the computer; the normally open contacts A1 and E1, B1 and F1 of the relay are shorted; the normally closed contacts A3 and D3, B3 Short circuit with C3; the movable contact E2 of the relay is connected to the positive pole of the diode of the first photocoupler in the acquisition circuit through the first current limiting resistor, and the movable contact D2 is connected to the negative pole of the diode of the first optocoupler in the acquisition circuit; the relay The movable contact F2 of the second current-limiting resistor is connected to the positive pole of the diode of the second photocoupler in the acquisition circuit, and the movable contact C2 is connected to the negative pole of the diode of the second photocoupler; the movable contacts A2 and B2 of the relay are respectively used as The input interface of the external switch status bit of the computer; the normally closed contacts E3 and F3 of the relay are connected to the power positive of the computer; the normally open contacts D1 and C1 of the relay are connected to the power ground of the computer.

Preferably, the relay adopts domestic JRC-600M, the contact form of the relay is 6Z, the rated voltage of the coil is 6-27Vd.c., and the contact load is not greater than 1A.

Preferably, the domestic HT281-4 photocoupler is used in the acquisition circuit.

Preferably, the collector-emitter voltage of the acquisition circuit does not exceed 40V d.c.

Preferably, the current limiting resistor is used to ensure that the input current meets the requirement of 5-20mA under a certain voltage.

The invention also provides a method for using the device to identify and collect the state of the external switch value of the computer.

Preferably, the following steps are included:

When the computer's external switch status bit is low, the computer does not issue a switching command, and the contacts of the relay do not move; the switch status 1 and switch status 2 input from the movable contacts A2 and B2 of the relay pass through the relay contacts. The connection line is connected to the negative poles of the diodes of the third and fourth photocouplers of the acquisition circuit; the power supply of the computer is connected to the acquisition circuit through the third and fourth current limiting resistors through the normally closed contact E3 and F3 contact line of the relay The anodes of the diodes of the third and fourth photocouplers; thus the acquisition circuit can normally identify the low level of the switch state, and output to the CPU processor;

When the computer’s external switching value state bit is high level, the computer sends a switching command, and the relay contacts act; the switching value state 1 and switching value state 2 respectively input from the movable contacts A2 and B2 of the relay are connected through the relay contacts. The third and fourth current-limiting resistors are connected to the anodes of the diodes of the third and fourth photocouplers of the acquisition circuit; the power supply ground of the computer is connected to the third and fourth acquisition circuits by the normally open contacts D1 and C1 of the relay. The cathode of the diode of the fourth photocoupler; thus, the acquisition circuit can normally identify the high level of the switching value state and output it to the CPU processor.

The invention also provides an application of the device in the technical field of computer control.

(3) Beneficial effects

The present invention provides an automatic acquisition device for high and low level levels in a small current state, which can realize the CPU processor acquisition of high and low level switching values in a small current state. When the external switching value of the computer is in a changing state, no manual setting is required ( switch), the device can be automatically recognized.

Description of drawings

Fig. 1 a is the circuit diagram of the low level bit state acquisition circuit;

Fig. 1b is a circuit diagram of a high level bit state acquisition circuit;

Fig. 2 is the circuit diagram that adopts jumper mode to set the different status bit acquisition circuits of high and low levels;

Fig. 3 is a circuit diagram of the high and low level state automatic acquisition device of the present invention.

Detailed ways

In order to make the purpose, content, and advantages of the present invention clearer, the specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 3, the high and low level state automatic acquisition device under a small current provided by the present invention includes two parts, a small current relay and a collection circuit; Control; the acquisition circuit is used to convert the state of the external switch value of the computer into the identification state bit of the CPU processor.

In this embodiment, the small current relay adopts the domestic JRC-600M, which has six sets of changeover contacts, and the contact load is 1A. One small current relay is responsible for the switching control of the high and low level state of the 2-bit switching value. The contact form of the small current relay It is 6Z, the coil rated voltage is 6~27Vd.c., and the contact load is not more than 1A; the domestic HT281-4 photocoupler is used in the acquisition circuit, and each chip is responsible for the identification of 4-bit switch state transition, which can be increased according to actual use requirements Number of chips; in this embodiment, the number of small current relays and acquisition circuits is 1 each, and the acquisition circuit includes four photocouplers and four current-limiting resistors. The input current of the acquisition circuit is 5-20mA, and the collector-emitter voltage does not exceed 40V d.c.; the function of the current-limiting resistor is to ensure that the input current meets the requirements of 5-20mA under a certain voltage.

The negative pole of the coil of the small current relay is connected to the power ground of the computer, and the positive pole of the coil is connected to the positive pole of the switching command issued by the computer; the normally open contacts A1 and E1, B1 and F1 of the small current relay are shorted; the normally closed contacts A3 and D3, B3 and C3 is short-circuited; the movable contact E2 of the small current relay is connected to the positive pole of the diode of the first optocoupler in the acquisition circuit by the first current limiting resistor, and the movable contact D2 is connected to the negative pole of the diode of the first optocoupler in the acquisition circuit; The movable contact F2 of the small current relay is connected to the positive pole of the diode of the second photocoupler in the acquisition circuit through the second current limiting resistor, and the movable contact C2 is connected to the negative pole of the diode of the second photocoupler; the movable contact of the small current relay A2 and B2 are respectively used as the input interface of the computer's external switch status; the normally closed contacts E3 and F3 of the small current relay are connected to the positive power supply of the computer; the normally open contacts D1 and C1 of the small current relay are connected to the power supply ground of the computer .

When the computer's external switch status bit is low level, the computer does not issue a switching command, and the contact of the small current relay does not move; the switch value state 1 and switch value state 2 input by the moving contacts A2 and B2 of the small current relay respectively pass through The relay contact connection is connected to the negative poles of the diodes of the third and fourth photocouplers of the acquisition circuit; the power supply of the computer is passing through the third and fourth current limiting through the normally closed contact E3 and F3 contact connection of the small current relay The resistor is connected to the anodes of the diodes of the third and fourth photocouplers of the acquisition circuit; thus the acquisition circuit can normally identify the low level of the switching value and output it to the CPU processor.

When the computer's external switch status bit is high, the computer sends a switching command, and the contact of the small current relay acts; the switch status 1 and switch status 2 input by the moving contacts A2 and B2 of the small current relay respectively pass through the relay contacts The connection line is connected to the anodes of the diodes of the third and fourth photocouplers of the acquisition circuit through the third and fourth current-limiting resistors; the power supply ground of the computer is connected to the The cathodes of the diodes of the third and fourth photocouplers of the acquisition circuit; thus, the acquisition circuit can normally identify the high level of the switch state and output it to the CPU processor.

Therefore, the high and low level state automatic acquisition device under low current of the present invention can identify and collect the external switching value state of the computer without manual setting.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (10)

1. A high and low level state automatic acquisition device under a small current is characterized in that, comprising two parts of a relay and an acquisition circuit; the relay is used to realize switching control of the high and low level states of the external switching quantity of the computer; the acquisition circuit It is used to convert the external switch state of the computer into the CPU processor identification state bit. 2. The device according to claim 1, wherein the relay is equipped with six sets of changeover contacts, which are responsible for the switching control of the high and low level states of the 2-bit switching value, and the acquisition circuit is responsible for the state transition identification of the 4-bit switching value, Including four photocouplers and four current limiting resistors, the input current of the acquisition circuit is 5-20mA. 3. The device according to claim 2, wherein the negative pole of the coil of the relay is connected to the power ground of the computer, and the positive pole of the coil is connected to the positive pole of the switching command sent by the computer; the normally open contacts A1 and E1, B1 and F1 of the relay Short circuit; normally closed contact A3 and D3, B3 and C3 short circuit; the movable contact E2 of the relay is connected to the anode of the diode of the first photocoupler in the acquisition circuit through the first current limiting resistor, and the movable contact D2 is connected to the acquisition circuit The negative pole of the diode of the first optocoupler; the movable contact F2 of the relay is connected to the positive pole of the diode of the second optocoupler in the acquisition circuit through the second current limiting resistor, and the movable contact C2 is connected to the diode of the second optocoupler Negative pole; the movable contacts A2 and B2 of the relay are respectively used as the input interface of the external switch state of the computer; the normally closed contacts E3 and F3 of the relay are connected to the positive power supply of the computer; the normally open contacts D1 and C1 of the relay are connected to the computer the power ground. 4. The device according to claim 3, wherein the relay adopts domestic JRC-600M, the contact form of the relay is 6Z, the rated voltage of the coil is 6-27Vd.c., and the contact load is not greater than 1A. 5. The device according to claim 3, characterized in that, the domestic HT281-4 optocoupler is used in the acquisition circuit. 6. The device according to claim 3, wherein the collector-emitter voltage of the acquisition circuit does not exceed 40Vd.c. 7. The device according to claim 3, wherein the current-limiting resistor is used to ensure that the input current meets the requirement of 5-20 mA under a certain voltage. 8. A method for using the device according to any one of claims 3 to 7 to identify and collect the state of the external switch of the computer. 9. The method of claim 8, comprising the steps of: When the computer's external switch status bit is low, the computer does not issue a switching command, and the contacts of the relay do not move; the switch status 1 and switch status 2 input from the movable contacts A2 and B2 of the relay pass through the relay contacts. The connection line is connected to the negative poles of the diodes of the third and fourth photocouplers of the acquisition circuit; the power supply of the computer is connected to the acquisition circuit through the third and fourth current limiting resistors through the normally closed contact E3 and F3 contact line of the relay The anodes of the diodes of the third and fourth photocouplers; thus the acquisition circuit can normally identify the low level of the switch state, and output to the CPU processor; When the computer’s external switching value state bit is high level, the computer sends a switching command, and the relay contacts act; the switching value state 1 and switching value state 2 respectively input from the movable contacts A2 and B2 of the relay are connected through the relay contacts. The third and fourth current-limiting resistors are connected to the anodes of the diodes of the third and fourth photocouplers of the acquisition circuit; the power supply ground of the computer is connected to the third and fourth acquisition circuits by the normally open contacts D1 and C1 of the relay. The cathode of the diode of the fourth photocoupler; thus, the acquisition circuit can normally identify the high level of the switching value state and output it to the CPU processor. 10. An application of the device according to any one of claims 1 to 7 in the field of computer control technology.

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