Security old bird summary: monitoring system engineering 100 questions

Chatting with friends today, when it comes to how to do marketing, is actually a manifestation of influence in actual work.

Turned through the old data, found an article, talking about 100 monitoring system engineering. Although there are some problems in the inside are outdated, but people who come from the analog era is still feeling very kind, it is because of the accumulation of the simulation era, only in the current era of network monitoring and Internet marketing performance.

So come out today to share with everyone, the original old knowledge, see if you can express new highlights!

1. Why use a regulated power supply in the power supply system?

Prevent damage to monitoring equipment due to power supply voltage fluctuations (high, low).

2. Is the power supply stable to the server monitoring system?

Unstable power can prevent the computer from working properly or even damage the computer's power supply or the motherboard.

3. What are the main functions and parameters to pay attention to when selecting a regulated power supply?

A: Output power B: Overvoltage protection function C: Overcurrent protection function D: Output voltage range AC110 or AC220

4, how to choose the power supply?

According to the actual situation, the output power of the regulated power supply is required to be greater than or equal to the sum of the total power of all the electrical equipment.

5, how to use the power supply?

A: Connect the AC AC 220v power supply to the input of the regulated power supply first.

B: Connect the power cord of the equipment requiring voltage protection to the AC 220v output of the regulated power supply.

6. What is UPS power?

Uninterrupted power supply. With a stable, stable frequency, anti-jamming, anti-surge function.

Function: If the power is suddenly cut off, the UPS can continue to supply power to the powered device for a period of time.

7. Main functional parameters of UPS power supply?

A: Maximum current discharge time B: Surge protection function.

8, UPS power selection method?

A: According to the power consumption of the equipment to be protected.

B: According to the need to protect the equipment after the power is off, it needs to maintain the power supply time.

9. What are the benefits of UPS power supply for computers?

A: Prevent damage to the computer due to unstable voltage or sudden power failure.

B: Provides the time to save data and shut down after power off.

10. What is the function of the leakage protector?

When electricity leakage occurs in the power equipment, the power is automatically cut off in time to protect the safety of personnel and equipment.

11. How to install the leakage protector?

The earth leakage protector is used together with the air switch and is installed at the front end of the equipment power supply.

12. Leakage protection device leakage protection function test?

When the power is on, press the leakage test button (usually yellow), the air switch should jump off; at the same time, the blue button jumps. The air switch can only be closed after pressing the blue button.

13. How to use the leakage protector?

A: The protector is used with the air switch.

B: AC power first enters air switch → air switch output → leakage protector input → leakage protector output → load.

14. Does the leakage protector be damaged?

A: Leave the leakage protector empty.

B: Does the power-on test function properly?

15, infrared light works?

Multiple infrared light beams are emitted by lighting up multiple groups of infrared light emitting diodes (λ=850 nm).

16. How important is the infrared light in the monitoring system?

A: The light source compensation is provided when the light is insufficient, so that the camera imaging is clear.

B: Guaranteed the concealment of the monitoring system.

17, the correct choice of infrared light method?

A: According to the area of ​​the monitored area.

B: Distance from the camera to the monitoring target.

18, infrared light installation in the monitoring system?

It is generally mounted below the camera with the same angle as the camera lens.

19. Is it easy to determine if infrared light is damaged?

With the camera in the infrared lamp, when the infrared lamp works normally, the infrared lamp can be clearly seen through the monitor. If the infrared lamp does not light, the infrared lamp may be damaged.

20, the main function and parameters of conventional infrared light?

A:: Center wavelength λ = 850nm B: Effective distance 10 (m) ~ 100 (m)

C: Emission angle 70 degrees D: Power AC 130~260V

E: Operating Temperature -30°C~60°C F: Power Consumption 12W

G: Waterproof grade GB55 H: Structure All weather aluminum

21. How to install and use conventional infrared lamps?

A: Usually installed under the camera.

B: The power supply is AC130V to AC260V.

22, the classification of multimeter?

A: Digital Table B: Analog Meter

23. How to measure the position of the multimeter during use?

ACV: AC voltage file Ω resistor file

ACA: AC Current Files →|- Diodes

DCV: DC voltage profile DCA: DC current profile

24, multimeter in the measurement process range selection method?

A: When you do not know the range of the measured value, you should choose its maximum range for measurement.

B: If you know the range, you can choose the appropriate range to increase the accuracy.

25. How to use the multimeter to test the short circuit and breakage of the line during the construction of the three-level network wiring?

Use the multimeter's resistance file for path detection; short circuit detection.

26. How to use a multimeter to detect the power of the monitoring equipment during the maintenance of the tertiary network?

A: AV controller. Power supply: input AC220V power board output +5 (3)-5 (one)

B: The power of the control host is: 220V

C: The monitor power supply is:

27. How to use a digital multimeter to measure AC voltage?

Choose ACV 750V file

28. How to use a digital multimeter to measure DC voltage?

Select DCV 20V file

29, DVR correct switch method?

A: Open the peripheral first and then open the host.

B: Turn off the host first and then close the peripherals.

30. Simple maintenance and management of DVR?

A: Check each cable.

B: Dust is always removed.

C: The DVR hard disk is often sorted.

31. When the hard disk recorder suddenly loses power during operation, it should be handled as such.

A: Turn off all peripheral power.

B: When an incoming call is made, the peripherals are opened first, and then the mainframe is powered up.

C: After the system self-test is completed, run the operating system.

32, the role of sound card in DVR?

Analog signals and digital-to-analog conversions are performed on the audio signals.

33. What is the function and function of the interface on the sound card in the DVR?

A: SPK, B: LINE IN, C:MIC

A: sound output B: linear input C: mic input

34, the classification of speakers?

A: Active B: Passive

35, speaker selection method?

A: active, passive B: antimagnetic

C: Power D: Material E: Sound quality

36, DVR capture card in the server-side monitoring system in the role?

Video signal acquisition converts analog video signals to digital signals.

37. The function of each interface of the acquisition card on the DVR?

A: Lotus Block: Video Input Interface (RCA)

B: S - video input interface

C: +5V or +12V output connector

38. What are the main functions and roles of video and audio controllers in server-side monitoring systems?

A: Video signal acquisition. B: Sending and receiving audio signals.

C: Built-in modem remote transmission module. D: Remote access connection.

39. Names and functions of interfaces on video and audio controllers?

A: BNC Block (8-channel video input)

B: BNC block (local output) for local video output.

C: BNC Block (Local Expansion Input) for AV Controller Level (Slave Video Output)

D: D-type 15 holes (used to connect the monitoring host) for data audio connection.

E: D-type 9-pin (data cable)

40. What are the names of the input and output connections on the video and audio controller and their role in the system?

A: D-type 15-core connection is the connection with the control host for communication.

B: The D-type 9-pin connection is the connection between the computer and the computer.

41. What are the main functions and roles of the monitoring host in the server-side monitoring system?

A: Data audio communication with AV controller.

B: Data audio communication with monitor slaves.

42. Monitor the name and function of the interface on the host?

A: RJ-45 interface Data, audio, communication (between monitoring slaves)

B: Data communication and audio exchange between D15 pin and AV controller.

43. Monitor the name of the input and output connections on the host and what role it plays in the system?

RJ-45 4-pair twisted pair

A: 1 pair is RS-485 communication line.

B: 1 pair is audio IN.

C: 1 pair is audio OUT.

D: 1 pair is a backup line.

44. How to check the power supply status of the device through the status of the power indicator on the AV controller (or monitoring host) panel?

The power indicator is on to indicate that the power supply is normal. If it is off, check whether the power supply device is working properly.

45. What are the main functions and functions of monitoring slaves in the server-side monitoring system?

A: Call, alarm, intercom, check attendance function.

B: The video, audio, and data signals on the post are sent to the service duty room computer through a special cable.

C: The position of each post can be fully monitored by the computer in the duty duty room.

46, monitor the name of the interface on the handset and its function?

A: 5 BNCs are video interfaces (the first 4 are sentinel, pan/tilt, relay, extension, and output)

B: Three RJ-45 crystal blocks are communication interfaces (data, audio, and communication interfaces).

47. What are the names of the input and output connections on the slave monitor and their role in the system?

8-core cable: data audio communication line

Video Output (BNC) 75 Euro-5 coaxial cable is a video signal transmission line.

48. By checking the status of the digital display on the slave panel, check the operation status of the monitor slave power supply.

The digital display code "-----------" is the normal operation of the power supply after the subunit is powered on.

49, server-side monitoring system hardware components?

A: Computer and speaker, Mike.

B: AV controller.

C: Monitoring host (basic device).

50, server-side system hardware connection?

Computer COM1 - video and audio controller PCCOM1.

Computer COM2 - AV controller PCCOM2.

51, audio and video controller system connection?

MIC - Mike

SPK - Speaker

Video and audio controller local output (BNC) - capture card.

52. Communication protocol used between video and audio controller (or monitoring host, monitoring slave, and PTZ decoder)?

RS-485 protocol is used between devices.

53, the communication protocol used between video and audio controllers and computers?

The main use of RS-232 protocol

54. What kind of compression algorithm is used mainly when connecting remotely?

The main use of compact adaptive dynamic prediction image compression algorithm.

55, video and audio controller using the video amplifier circuit and chip?

The video chip in the video and audio controller mainly uses the MAX440

56. What role does PTZ play in monitoring systems?

By controlling the pan/tilt to perform horizontal and vertical movements and controlling the pan/tilt camera to perform zooming and focusing operations, the monitoring area is monitored more completely and clearly.

57, PTZ decoder function?

Decode the received data command, and then control the PTZ rotation and camera focus, zoom and other operations.

58. PTZ's working voltage classification?

PTZ operating voltage is generally divided into 24V and 220V AC.

59. Is the judgment method of the communication status between the PTZ decoder and the monitoring host normal?

The green indicator flashes for normal communication.

60, the classification of power lines?

A: indoor line B: outdoor waterproof line

61, centralized power supply in the choice of power line?

Requires the power cable to use an outdoor waterproof cable of more than 1.5 square feet.

62. Why should we choose centralized power supply in the monitoring system?

A: It is easy to control the power supply of the monitoring system.

B: It helps to protect the lightning protection of the power supply.

C: It is convenient to supply power to the monitoring system through the regulated power supply.

63, centralized power supply in the power line connection method and sealing requirements?

A: Welding power cord connector.

B: The outside of the joint is insulated with a thin heat shrinkable tube.

C: The joint is subjected to waterproofing and sealing with a hot melt, and a heat-shrinkable tube is put on the joint.

D: Heating melts the silica gel and tightens the heat shrink tube.

64, centralized power supply power line connection and sealing tools?

A: Electric iron B: Solder C: Heat-shrinkable tube D: Hot-melt silicone

E: Hot air gun F: Stripping pliers

65. How to choose route routing in the process of server monitoring system cabling?

The server-side engineering wiring may adopt a combination of serial, star, and serial star.

66, several ways of line laying in the server monitoring system?

A: Laying along the wall B: Overhead laying C: Laying underground

67, server-side monitoring system requirements for AC power supply?

A: The power supply of the hard disk recorder requires the AC voltage to be 220V±5%.

B: The AC/AV controller, control panel, and monitoring sub-machine require the AC voltage to be +85V to +265V.

68, the role of the ground?

A: Functional grounding is grounding to ensure normal operation of electrical equipment or low noise in electrical systems.

Divided into: center point grounding, work grounding, logic grounding, shield grounding.

B: Protective earthing is grounding to prevent people or equipment from causing death or injury by electric shock.

Divided into: shell protection grounding, building grounding, lightning protection grounding, electrostatic grounding, repeated grounding

69, the production of ground material required?

A: Galvanized steel pipe B: Expansion bolt

C: Galvanized steel strip D: Copper nose E: 10 square copper wire

70. What is the influence of the resistance value on the ground?

A: The salinity of the soil. B: The humidity of the soil.

C: The number and spacing of the ground pipe.

71. By improving the soil around the ground line, reduce the ground resistance and the required materials?

Brine, charcoal powder and other materials are required to inject salt water, charcoal powder, etc. into the ground pit.

72, the system requirements of the ground resistance?

The relationship between the size of the DC working grounding resistance, the connection method and the grounding should be determined according to the requirements of different electronic devices. Generally, the resistance should not be greater than 4Ω.

A: The grounding resistance of the safety protection grounding should not exceed 4Ω.

B: The grounding resistance of the safe working ground should not exceed 4Ω.

C: The grounding resistance of the lightning protection ground should not exceed 10Ω.

73, Thunder and other adverse weather hazards on the server monitoring system?

A: Interference with video signals, audio signals, and data communications.

B: Damage monitoring equipment.

74. The working principle and function of lightning protection module?

When the large current and high voltage enter the input of the lightning protection module, the lightning protection module opens the circuit between the input and the output. At the same time, the lightning protection module introduces high voltage and current into the earth through the ground wire.

75, lightning protection module installation method?

Installed at the forefront of electrical equipment.

76. Lightning protection circuit design and device used in video, audio, communication and power supply in video and audio controllers (monitoring host)?

A: Lightening diode B: Varistor C: Resettable fuse D: Inductor

Transient suppression diodes absorb power instantaneously from 400W to 600W and absorb tens of thousands of volts in a few microseconds.

77, video and audio controller (monitor host, monitor slave) in the power circuit on the use of the module power supply advantages?

When the supply voltage fluctuates (AC85 to AC265), the device is guaranteed to operate normally without being affected.

78, the working procedure of the modem?

A: Send a serial binary digital signal from a hard disk recorder.

B: These binary data are converted into analog signals by MODEM.

C: Send the analog signal to the telephone line.

D: The analog signal is converted into a binary digital signal through MODEM.

E: The hard disk recorder receives binary digital signals.

79, DVR data transmission method?

A: Serial transmission mode B: Parallel transmission mode

80, the classification of interference?

A: External interference B: System internal interference

81, camera classification?

A: Divided into color camera and black-and-white camera by color

B: According to the system, it is divided into PAL system and NTST system

82, camera imaging principle?

The image of the subject is focused on the CCD chip through the lens, and the CCD accumulates a corresponding proportion of charge according to the light intensity. The charge accumulated by each pixel moves outward point by point under the control of the video timing, and is filtered and amplified to form an image. Video signal output. The video signal is connected to the video input of a monitor or television to see the same video image as the original image.

83, the main parameters of the camera?

A: CCD target surface size B: Signal to noise ratio C: Minimum illumination D: Definition

84, how to match the lens?

In order to obtain the desired camera effects, attention should be paid to the six basic elements when selecting lenses:

A: Size of the subject B: Detail size of the subject C: Object distance D: Focal length

E: CCD camera target surface size F: Lens and camera system resolution

85, what kind of lens?

According to the application category:

A: Wide-angle lens: The viewing angle is more than 90 degrees, the observation range is relatively large, and the near image is deformed.

B: Standard lens: The angle of view is about 30 degrees, and the range of use is wider.

C: telephoto lens: within 20 degrees of viewing angle, focal length up to tens of millimeters or hundreds of millimeters.

D: Zoom Lens: The focal length of the lens is continuously variable, and the focal length can be changed from wide-angle to telephoto. The longer the focal length, the larger the image.

E: pinhole lens: used for concealed observations, often installed in places such as ceilings or walls.

86, the role and classification of protective cover?

The protective cover is an important component of the monitoring system. It is a protective device that makes the camera normally used in the presence of dust, rain, high and low temperatures.

Shields generally fall into two categories:

A: Indoor protective cover, its main function is to prevent the camera from falling ash and have a certain degree of security protection.

B: outdoor protective cover, this protective cover is generally all-weather protective cover, that is, regardless of wind, rain, snow, high temperature, low temperature and other harsh conditions, can make the camera installed in the protective cover to work properly. Therefore, this protective cover has the functions of cooling, warming, preventing rain, and preventing snow. At the same time, in order to allow the camera to normally capture images in rainy and snowy weather, controllable wipers are generally installed in front of the glass windows of all-weather protective hoods. In addition, there is also a hemispherical, spherical protective cover. This protective cover has a built-in universal adjustable support and is attractive in appearance.

87. Is it impossible for the Squadron Duty Watchroom to switch control with the post monitoring slave?

A: Check whether the production and connection between the RJ-45 connector of the post monitoring subunit and the control host is good.

B: If you cannot talk to all the posts, check the control host section.

C: If you cannot talk to a certain post, check the monitor subsection.

88. When monitoring the slave intercom with the host, I heard a small voice from the duty room. How to adjust?

If a single substation has this phenomenon, adjust the P1 potentiometer in the subboard. If all subunits are small, adjust the P2 potentiometer of the main board. (Clockwise direction)

89, the client can not establish a connection with the server, the server may be the cause of the failure?

A: The telephone line is faulty or the connection is incorrect.

B: Modem failure or incorrect connection.

C: The remote transmission module is faulty or the power supply is incorrect.

D: The AV controller board is faulty.

90, remote connection to the server-side telephone line requirements?

The analog telephone line of the telecommunication bureau has a transmission rate of not less than 10K, and the sound cannot be communicated when it is less than 15K.

91, the impact of power supply on the server monitoring system?

A: Unstable (high, low) power supply can damage the computer.

B: The power supply ripple system is too large for video interference.

92, server-side monitoring system regularly maintained content?

A, computer

B. Host Hardware Connection System

C, monitor the child

D. Video and data composite cables set up between the host and the monitoring slaves

93. How does the server-side monitoring system affect the video and audio signal quality and communication data of the surveillance system?

A, video interference

B, sound quality decline

C. The communication data cannot be properly delivered and the control is invalid or delayed.

94, speaker, Mike is a simple way to determine damage?

MIC and SPK are checked through the MIC and SPK ports on the sound card. Note: Do not mute the MIC and SPK items.

95, camera video image night blur or whitening solution?

A: The image is blurred at night and the focus of the camera is readjusted.

B: If the image is whitish, you can adjust the irradiation angle of the infrared lamp.

96. Is there a simple way to determine blue screen faults on the server monitor screen?

A. Check if the video signal route input is correct.

B. Check whether the contact of the video signal input Q9 with the video input controller video input is good or if the input Q9 head is welded.

C. Check if the video signal from this video camera is normal.

D. Check the video line for open circuit or short circuit.

E. Check if the camera or lens is damaged.

97. Causes of PTZ control failure:

A. The transmission line is too far away; B. The transmission line has interference; C. There are too many front-end control devices.

Solution: A, check the circuit, eliminate interference; B, add a code distributor at the back end

98, how hard disk video recorder video data save time?

1 channel 1 hour storage capacity (G) = stream * 3600 seconds / 8/1024/1000

99. What is dual stream?

That is, the hard disk recorder can output two kinds of code streams at the same time, the main code stream to the local video storage, and the sub-stream for remote access.

Different code rates can be set for the two types of code streams to adapt to different bandwidth transmission requirements.

100. Why does the camera appear black bars on the evening screen?

A. The power supply is insufficient; B. External interference; C. The camera itself is faulty.