CN208126171U - A kind of signal monitor and its device of anti-analog quantity jump - Google Patents

Abstract

The utility model discloses a device for preventing analog quantity jumps, which comprises: an input terminal receives a target analog quantity signal, an output terminal and the second input terminal of the first comparison module, the second input terminal of the second comparison module and a switching module The hysteresis module connected to the first input end of the trigger; the first input end receives the target analog signal, and the output end is connected to the first input end of the flip-flop; the first comparison module whose output end is connected to the second input end of the flip-flop Two comparison modules; flip-flops whose output terminals are connected to the control terminals of the switching module; switching modules whose output terminals are respectively connected to the second input terminals of the switching module and the first input terminals of the second comparison module. The device for preventing analog quantity jumping provided by the utility model can effectively prevent analog quantity signal jumping. The utility model also provides a signal monitor, which has corresponding technical effects.

Description

A signal monitor and its device for preventing analog quantity jump

technical field

The utility model relates to the technical field of analog quantity signal monitoring, in particular to a signal monitor and a device for preventing analog quantity jumps.

Background technique

Analog signal is a common signal. In many fields, it is necessary to monitor the analog signal, such as the monitoring of the liquid level of the desulfurization absorption tower and the monitoring of the gypsum slurry in the power plant, the monitoring of the water level of the condenser, and the monitoring of the water level of the low-pressure heater.

Analog signals such as liquid level and flow rate are inertial variables and will not jump. If a jump is detected in the analog signal, it means that the detected jump signal is an inaccurate signal, also known as a false signal. Taking the water level monitoring of the low-pressure heater as an example, the leakage of the sampling pipeline or the abnormality of the thermal control equipment will cause an instantaneous jump in the measured water level signal, and the jump signal is a false signal. False signals may cause misoperation of control equipment, such as opening emergency drainage, which will bring hidden dangers to the safe operation of the unit.

To sum up, how to effectively prevent the jump of the analog signal is a technical problem urgently needed to be solved by those skilled in the art.

Utility model content

The purpose of the utility model is to provide a signal monitor and a device for preventing analog quantity jumps, so as to prevent analog quantity signals from jumping.

In order to solve the above technical problems, the utility model provides the following technical solutions:

A device for preventing analog jumps, the device comprising:

The input terminal receives the target analog signal, the output terminal is connected to the second input terminal of the first comparison module, the second input terminal of the second comparison module and the first input terminal of the switching module, and is used to convert the received The target analog signal is output from the output terminal after a preset time delay;

The first input terminal receives the target analog signal, and the output terminal is connected to the first input terminal of the flip-flop. The first comparison module is used for when the signal received by the first input terminal of the first comparison module is consistent with the When the difference between the signals received by the second input terminal of the first comparison module is greater than the preset first range, output the first control signal to the first input terminal of the flip-flop through the output terminal;

The second comparison module whose output terminal is connected to the second input terminal of the flip-flop, for when the signal received by the first input terminal of the second comparison module is consistent with the second input terminal of the second comparison module When the difference of the received signal is smaller than the preset second range, the second control signal is output to the second input end of the flip-flop through the output end; wherein, the upper limit of the second range is smaller than the upper limit of the first range an upper limit, the lower limit of the second range being greater than the lower limit of the first range;

The flip-flop whose output terminal is connected to the control terminal of the switching module is used to output a first state signal to the switching module when receiving the first control signal, and output a first state signal to the switching module when receiving the second control signal, outputting the second status signal;

The switching module whose output terminals are respectively connected to the second input terminal of the switching module and the first input terminal of the second comparison module is used to output the switching module when receiving the first state signal. The signal at the second input terminal, when receiving the second state signal, outputs the signal at the first input terminal of the switching module.

Preferably, the first comparison module includes:

The first input end receives the target analog signal, the second input end is connected to the output end of the lag module, and the first adder is used to determine the difference between the signal received by the first input end and the signal received by the second input end. difference;

The first high-low comparison module whose input terminal is connected to the output terminal of the first adder is used to send the trigger to the The first input terminal of the device outputs the first control signal.

Preferably, the first high-low comparison module includes:

The first high-low comparator whose input terminal is connected to the output terminal of the first adder is used for determining that when the difference value output by the first adder is greater than the upper limit of the preset first range, the first output terminal outputs the first signal, when it is determined that the difference output by the first adder is less than the lower limit of the preset first range, the second output terminal outputs the second signal;

The first input terminal is connected to the first output terminal of the first high-low comparator, and the second input terminal is connected to the second output terminal of the first high-low comparator, and is used for receiving the first high-low comparator. signal or the second signal, output the first control signal to the first input end of the flip-flop through the output end.

Preferably, the second comparison module includes:

The first input terminal is connected to the output terminal of the switching module, and the second input terminal is connected to the output terminal of the hysteresis module. The second adder is used to determine the signal received by the first input terminal and the signal received by the second input terminal. the difference of the signal;

The second high-low comparison module whose input terminal is connected to the output terminal of the second adder is used to send a signal to the trigger via the output terminal The second input terminal of the device outputs the second control signal.

Preferably, the second high-low comparison module includes:

The second high-low comparator whose input terminal is connected to the output terminal of the second adder is used to output the first output terminal when it is determined that the difference output by the second adder is less than the preset second range upper limit. Three signals, when it is determined that the difference output by the second adder is greater than the preset lower limit of the second range, the second output terminal outputs a fourth signal;

The first input terminal is connected to the first output terminal of the second high-low comparator, and the second input terminal is connected to the second output terminal of the second high-low comparator, and is used for receiving the third signal and the fourth signal, the second control signal is output to the second input end of the flip-flop through the output end.

Preferably, it also includes:

An alarm module that is connected to the switching module and used to output prompt information when the signal output by the switching module is the signal input by the second input terminal of the switching module.

Preferably, it also includes:

A recording module connected with the alarm module and used for recording the time when the alarm module outputs prompt information.

A signal monitor, which includes the device for preventing analog jumps according to any one of the above.

Applying the technical solution provided by the utility model, the hysteresis module outputs the received target analog signal after a preset time delay, and the first comparison module respectively receives the target analog signal and the signal output by the hysteresis module, that is to say, the second The time interval between the two signals received by a comparison module is a preset time length. When the first comparison module determines that the difference between the two signals is greater than the first range, it means that the target analog signal has jumped, and by sending the first control signal to the flip-flop, the flip-flop outputs the first state to the switching module signal, when the switching module receives the first state signal, the signal output by the output terminal is the signal of the second input terminal. Since the second input terminal of the switching module is connected to its own output terminal, that is to say, when the target analog signal jumps, the signal output by the output terminal will not change, and the signal before the jump will be kept as the final output signal . Both the output signal of the switching module and the output signal of the hysteresis module are connected to the second comparison module, and when the difference between the two signals is lower than the second range, it means that the target analog signal has returned to a normal range. The second comparison module sends the second control signal to the flip-flop, the flip-flop outputs the second state signal to the switch module, and the signal output by the switch module becomes the signal of the first input terminal again, that is, the signal input by the lag module is output, which makes The output signal returns to the normal target analog signal.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a kind of structural representation of the device of anti-analogue jump in the utility model;

Fig. 2 is another structural schematic diagram of the device for preventing analog jumps in the present invention.

Detailed ways

The core of the utility model is to provide a device for preventing analog quantity jumps. When the analog quantity signal jumps, the value before the jump is output. When the analog quantity signal returns to normal, the normal output of the output terminal is restored.

In order to enable those skilled in the art to better understand the solution of the utility model, the utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Fig. 1, which is a schematic structural diagram of the device for preventing analog jumps in the utility model, and the device for preventing analog jumps includes:

The input terminal receives the target analog signal, and the output terminal is connected to the second input terminal of the first comparison module 200, the second input terminal of the second comparison module 300 and the first input terminal of the switching module 500. The received target analog signal is output from the output terminal after a preset time delay.

In FIG. 1 , 1 and 2 of the first comparison module 200 represent the first input terminal and the second input terminal of the first comparison module 200 respectively, and 1 and 2 of the second comparison module 300 represent the first input terminal of the second comparison module 300 respectively. An input end and a second input end, 1 and 2 of the flip-flop 400 respectively represent the first input end and the second input end of the flip-flop 400, and 1 and 2 of the switching module 500 represent the first input end and the second input end of the switching module 500 respectively. the second input.

The input terminal of the hysteresis module 100 receives a target analog signal, which may be an analog signal such as water level or pipeline flow. The hysteresis module 100 outputs the received target analog signal from the output terminal after a preset time delay, for example, after a delay of 2 seconds. In order to facilitate the understanding of this program, the target analog signal is used as the water level signal for illustration. For example, the delay of the hysteresis module 100 is set to 2 seconds, and the water level signal is the normal value of 500mm at time A. The output terminal of the module 100 outputs a water level signal of 500mm. It should be pointed out that the preset duration of the delay by the lagging module 100 can be set and adjusted according to actual conditions, for example, it can be set according to differences in target analog signals. The output terminal of the hysteresis module 100 is respectively connected with the second input terminal of the first comparison module 200 , the second input terminal of the second comparison module 300 and the first input terminal of the switching module 500 .

The first input end receives the target analog signal, and the output end is connected to the first input end of the flip-flop 400. The first comparison module 200 is used for when the signal received by the first input end of the first comparison module 200 is compared with the first comparison module. When the difference between the signals received by the second input end of the flip-flop 400 is greater than the preset first range, the first control signal is output to the first input end of the flip-flop 400 through the output end.

The first comparison module 200 has two input terminals, any one of which can be used as the first input terminal to receive the target analog signal, and the other is connected to the output terminal of the lag module 100 as the second input terminal, and receives the output of the lag module 100. Signal. The first comparison module 200 calculates the difference between the signal received by the first input terminal and the signal received by the second input terminal, and when the difference is greater than the preset first range, it outputs to the first input terminal of the flip-flop 400 through the output terminal first control signal.

Still taking the above-mentioned water level at time A as 500mm, and the delay module 100 outputting a water level signal of 500mm at time B after 2 seconds as an example, it may be assumed that the target analog signal jumps at time B, for example, the false signal of the jump is 560mm. Then the first comparison module 200 receives a water level signal of 560 mm from the first input end, and receives a water level signal of 500 mm from the second input end. For example, the first range is -50 to 50. When the first comparison module 200 calculates the difference between 560mm and 500mm, and the difference exceeds the range of -50 to 50, then the first comparison module 200 sends the first input of the flip-flop 400 output the first control signal. Of course, the specific numerical values in the first range can be set and adjusted according to actual conditions.

The second comparison module 300 whose output terminal is connected to the second input terminal of the flip-flop 400 is used to compare the signal received by the first input terminal of the second comparison module 300 with the signal received by the second input terminal of the second comparison module 300 When the difference is smaller than the preset second range, the second control signal is output to the second input end of the flip-flop 400 through the output end; wherein, the upper limit of the second range is smaller than the upper limit of the first range, and the lower limit of the second range is greater than the first the lower limit of a range;

The flip-flop 400 whose output end is connected to the control end of the switching module 500 is used to output the first state signal to the switching module 500 when receiving the first control signal, and output the second state signal when receiving the second control signal;

The switching module 500 whose output terminals are respectively connected to the second input terminal of the switching module 500 and the first input terminal of the second comparison module 300 is used to output the signal of the second input terminal of the switching module 500 when receiving the first state signal, When receiving the second state signal, output the signal of the first input end of the switching module 500 .

When the flip-flop 400 receives the first control signal from the first comparison module 200 through the first input terminal, it means that the target analog signal has jumped, and the flip-flop 400 outputs the first state signal to the control terminal of the switching module 500 . In the above example, when the water level jumps from 500mm to 560mm within 2 seconds, the trigger 400 outputs the first status signal to the control terminal of the switching module 500 .

The signal output by the switching module 500 is the signal obtained by subjecting the target analog signal to anti-jump processing in this solution. The control terminal of the switching module 500 is connected to the output terminal of the flip-flop 400 , and when the control terminal receives the first state signal, the switching module 500 outputs the signal of the second input terminal. Since the second input terminal of the switching module 500 is connected to the output terminal of the switching module 500, in the above example, when the water level jumps from 500mm to 560mm within 2 seconds, the output terminal of the switching module 500 outputs a water level signal of 500mm If it is connected to the second input terminal of the switching module 500, the switching module 500 will continuously output a water level signal of 500 mm. That is to say, when the target analog signal jumps, the signal output by the switching module 500 will be the value before the jump and remain unchanged.

The output signal of the switching module 500 is also connected to the first input terminal of the second comparison module 300 , and the second input terminal of the second comparison module 300 receives the signal output by the hysteresis module 100 . Still with the water level signal of 500mm, for example, the signal output by the delay module 100 at time C is 520mm, the water level signal of this 520mm and the water level signal of 500mm output by the switching module 500 are input to the second comparison module 300, and the second comparison module 300 calculates the difference Then compare the difference with a preset second range, for example, the second range is -30 to 30. It should be pointed out that a certain numerical value in this scheme exceeds the first range, which means that the numerical value is greater than the upper limit of the first range or less than the lower limit of the first range, and the first range is a continuous interval. Correspondingly, a value lower than the second range means that the value is less than the upper limit of the second range and greater than the lower limit of the second range, that is to say, the value is within the coverage of the second range, and the second range is also a continuous interval.

When the difference between the signal received by the first input terminal of the second comparison module 300 and the signal received by the second input terminal of the second comparison module 300 is less than the preset second range, it means that the target analog signal at this moment returns to normal , then the second comparison module 300 outputs the second control signal to the second input end of the flip-flop 400 through the output end.

After receiving the second control signal, the flip-flop 400 sends a second state signal to the switching module 500 . When the switching module 500 receives the second state signal, the signal output by the output terminal is the signal of the first input terminal. Since the first input terminal of the switching module 500 is connected to the output terminal of the hysteresis module 100, that is, when the target analog signal recovers When normal, the switch module 500 re-outputs the signal output by the lag module 100 , that is, a normal signal.

The upper limit of the second range is less than the upper limit of the first range, and the lower limit of the second range is greater than the lower limit of the first range. That is to say, the area covered by the second range is a part of the area covered by the first range. For example, in the above example, the first range is -50 to 50, and the second range is -30 to 30. Therefore, in this solution, at the same moment, the flip-flop 400 will not receive the first control signal and the second control signal at the same time.

Applying the technical solution provided by the utility model, the hysteresis module outputs the received target analog signal after a preset time delay, and the first comparison module respectively receives the target analog signal and the signal output by the hysteresis module, that is to say, the second The time interval between the two signals received by a comparison module is a preset time length. When the first comparison module determines that the difference between the two signals is greater than the first range, it means that the target analog signal has jumped, and by sending the first control signal to the flip-flop, the flip-flop outputs the first state to the switching module signal, when the switching module receives the first state signal, the signal output by the output terminal is the signal of the second input terminal. Since the second input terminal of the switching module is connected to its own output terminal, that is to say, when the target analog signal jumps, the signal output by the output terminal will not change, and the signal before the jump will be kept as the final output signal . Both the output signal of the switching module and the output signal of the hysteresis module are connected to the second comparison module, and when the difference between the two signals is lower than the second range, it means that the target analog signal has returned to a normal range. The second comparison module sends the second control signal to the flip-flop, the flip-flop outputs the second state signal to the switch module, and the signal output by the switch module becomes the signal of the first input terminal again, that is, the signal input by the lag module is output, which makes The output signal returns to the normal target analog signal.

In a specific implementation manner of the present utility model, the first comparison module 200 includes:

The first input end receives the target analog signal, and the second input end is connected to the output end of the lag module 100. The first adder 210 is used to determine the difference between the signal received by the first input end and the signal received by the second input end. ;

The first high-low comparison module whose input terminal is connected to the output terminal of the first adder 210 is used to send the output terminal to the first high-low comparison module of the flip-flop 400 when it is determined that the difference output by the first adder 210 is greater than the preset first range. An input end outputs a first control signal.

In this specific implementation of the present invention, the first adder 210 and the first high-low comparison module can be used as the first comparison module 200 . The first input end of the first adder 210 receives the target analog signal, which is equivalent to the first input end of the first comparison module 200, and the second input end of the first adder 210 is connected to the output end of the hysteresis module 100, which is equivalent to At the second input terminal of the first comparison module 200 , the adder can perform a difference between the signal received at the first input terminal and the signal received at the second input terminal. The input end of the first high-low comparison module is connected to the output end of the first adder 210, when it is determined that the difference value output by the first adder 210 is greater than the preset first range, the first input to the flip-flop 400 is passed through the output end output the first control signal.

During specific implementation, the first high-low comparison module may include a first high-low comparator 220 and an OR gate device 230, as shown in FIG. 2 :

The input terminal of the first high-low comparator 220 is connected with the output terminal of the first adder 210, when it is determined that the difference value output by the first adder 210 is greater than the upper limit of the preset first range, the first output terminal outputs the first signal , when it is determined that the difference output by the first adder 210 is smaller than the lower limit of the preset first range, the second output terminal outputs a second signal. Both the first signal and the second signal may be high-level signals, which may be represented by 1.

The first input terminal of the OR gate 230 is connected to the first output terminal of the first high-low comparator 220 , and the second input terminal is connected to the second output terminal of the first high-low comparator 220 . Any input terminal of the OR gate device 230 can be used as the first input terminal, and when any input terminal receives a high-level signal, the first control signal is output to the first input terminal of the flip-flop 400 through the output terminal. The first control signal can also be a high level signal.

In a specific implementation manner of the present utility model, the second comparison module 300 may include:

The first input terminal is connected to the output terminal of the switching module 500, and the second input terminal is connected to the output terminal of the lag module 100. The second adder 310 is used to determine the signal received by the first input terminal and the signal received by the second input terminal. the difference;

The second high-low comparison module whose input terminal is connected to the output terminal of the second adder 310 is used for sending the output terminal to the second high-low comparison module of the flip-flop 400 when it is determined that the difference output by the second adder 310 is less than the preset second range. The two input terminals output the second control signal.

In this embodiment, the first input terminal of the second adder 310 is connected to the output terminal of the switching module 500, which is equivalent to the first input terminal of the second comparison module 300, and the second input terminal is connected to the output terminal of the lagging module 100. The connection is equivalent to the second input terminal of the second comparison module 300 . The second adder 310 can calculate the difference between the signal received by the first input end and the signal received by the second input end, and output the difference to the second high-low comparison module, when the second high-low comparison module determines that the second adder When the difference output by 310 is smaller than the preset second range, the second control signal is output to the second input end of the flip-flop 400 through the output end.

During specific implementation, the second high-low comparison module may include a second high-low comparator 320 and an AND gate 330, as shown in FIG. 2 :

The input end of the second high-low comparator 320 is connected with the output end of the second adder 310, when it is determined that the difference value output by the second adder 310 is less than the preset second range upper limit, the first output end outputs the third signal, When it is determined that the difference output by the second adder 310 is greater than the preset lower limit of the second range, the second output terminal outputs a fourth signal. Both the third signal and the fourth signal may be high-level signals.

The first input end of the AND gate 330 is connected to the first output end of the second high-low comparator 320, and the second input end is connected to the second output end of the second high-low comparator 320. When receiving the third signal and the fourth signal , the second control signal is output to the second input end of the flip-flop 400 through the output end. The second control signal can also be a high level signal. In a specific implementation, the flip-flop 400 can be an RS flip-flop, wherein the R terminal can be used as the second input terminal of the flip-flop 400 , and the S terminal can be used as the first input terminal of the flip-flop 400 .

In a specific embodiment of the present utility model, it may also include:

It is connected with the switch module 500 and is used for outputting an alarm module of prompt information when the signal output by the switch module 500 is the signal input by the second input terminal of the switch module 500 .

When the signal output by the switching module 500 is the signal input by the second input terminal of the switching module 500, it indicates that the target analog signal has jumped. In this embodiment of the present invention, the alarm module and the switching module 500 can be used connection, when the target analog signal jumps, the alarm module outputs a prompt message to remind the staff that there is a false signal, and it is convenient for the staff to check and deal with the relevant equipment. The alarm module can be an alarm prompt light or a buzzer.

In a specific embodiment of the present utility model, it also includes:

The recording module is connected with the alarm module and is used for recording the time when the alarm module outputs prompt information. The recording module can record the time when the alarm module outputs the prompt information, which can facilitate the staff to check the historical records to determine when the target analog signal has jumped.

The utility model also provides a signal monitor, which may include the device for preventing analog jumps provided in any of the above-mentioned embodiments, which will not be repeated here.

In this paper, specific examples are used to illustrate the principle and implementation of the present utility model. The description of the above embodiments is only used to help understand the technical solution and core idea of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made to the utility model, and these improvements and modifications also fall into the protection of the claims of the utility model. within range.

Claims (8)

1. A device for preventing analog jumps, characterized in that it comprises: The input terminal receives the target analog signal, the output terminal is connected to the second input terminal of the first comparison module, the second input terminal of the second comparison module and the first input terminal of the switching module, and is used to convert the received The target analog signal is output from the output terminal after a preset time delay; The first input terminal receives the target analog signal, and the output terminal is connected to the first input terminal of the flip-flop. The first comparison module is used for when the signal received by the first input terminal of the first comparison module is consistent with the When the difference between the signals received by the second input terminal of the first comparison module is greater than the preset first range, output the first control signal to the first input terminal of the flip-flop through the output terminal; The second comparison module whose output terminal is connected to the second input terminal of the flip-flop, for when the signal received by the first input terminal of the second comparison module is consistent with the second input terminal of the second comparison module When the difference of the received signal is smaller than the preset second range, the second control signal is output to the second input end of the flip-flop through the output end; wherein, the upper limit of the second range is smaller than the upper limit of the first range an upper limit, the lower limit of the second range being greater than the lower limit of the first range; The flip-flop whose output terminal is connected to the control terminal of the switching module is used to output a first state signal to the switching module when receiving the first control signal, and output a first state signal to the switching module when receiving the second control signal, outputting a second state signal; The switching module whose output terminals are respectively connected to the second input terminal of the switching module and the first input terminal of the second comparison module is used to output the switching module when receiving the first state signal. The signal at the second input terminal, when receiving the second state signal, outputs the signal at the first input terminal of the switching module. 2. The device for preventing analog jumps according to claim 1, wherein the first comparison module comprises: The first input end receives the target analog signal, the second input end is connected to the output end of the lag module, and the first adder is used to determine the difference between the signal received by the first input end and the signal received by the second input end. difference; The first high-low comparison module whose input terminal is connected to the output terminal of the first adder is used to send the trigger to the The first input terminal of the device outputs the first control signal. 3. The device for preventing analog jumps according to claim 2, wherein the first high-low comparison module comprises: The first high-low comparator whose input terminal is connected to the output terminal of the first adder is used for determining that when the difference value output by the first adder is greater than the upper limit of the preset first range, the first output terminal outputs the first signal, when it is determined that the difference output by the first adder is less than the lower limit of the preset first range, the second output terminal outputs the second signal; The first input terminal is connected to the first output terminal of the first high-low comparator, and the second input terminal is connected to the second output terminal of the first high-low comparator, and is used for receiving the first high-low comparator. signal or the second signal, output the first control signal to the first input end of the flip-flop through the output end. 4. The device for preventing analog jumps according to claim 1, wherein the second comparison module comprises: The first input terminal is connected to the output terminal of the switching module, and the second input terminal is connected to the output terminal of the hysteresis module. The second adder is used to determine the signal received by the first input terminal and the signal received by the second input terminal. the difference of the signal; The second high-low comparison module whose input terminal is connected to the output terminal of the second adder is used to send the trigger to the The second input end of the device outputs the second control signal. 5. The device for preventing analog quantity jump according to claim 4, characterized in that, the second high-low comparison module comprises: The second high-low comparator whose input terminal is connected to the output terminal of the second adder is used to output the first output terminal when it is determined that the difference output by the second adder is less than the preset second range upper limit. Three signals, when it is determined that the difference output by the second adder is greater than the preset lower limit of the second range, the second output terminal outputs a fourth signal; The first input terminal is connected to the first output terminal of the second high-low comparator, and the second input terminal is connected to the second output terminal of the second high-low comparator, and is used for receiving the third signal and the fourth signal, the second control signal is output to the second input end of the flip-flop through the output end. 6. The device for preventing analog jumps according to any one of claims 1 to 5, further comprising: An alarm module that is connected with the switching module and used to output prompt information when the signal output by the switching module is the signal input by the second input terminal of the switching module. 7. The device for preventing analog jumps according to claim 6, further comprising: A recording module connected with the alarm module and used for recording the time when the alarm module outputs prompt information. 8. A signal monitor, characterized in that it comprises the device for preventing analog jumps according to any one of claims 1 to 7.