CN107741531B - Low-radiation processing system and testing method for server management network port - Google Patents
Low-radiation processing system and testing method for server management network port Download PDFInfo
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- CN107741531B CN107741531B CN201710800870.0A CN201710800870A CN107741531B CN 107741531 B CN107741531 B CN 107741531B CN 201710800870 A CN201710800870 A CN 201710800870A CN 107741531 B CN107741531 B CN 107741531B
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical group O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0807—Measuring electromagnetic field characteristics characterised by the application
- G01R29/0814—Field measurements related to measuring influence on or from apparatus, components or humans, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0864—Measuring electromagnetic field characteristics characterised by constructional or functional features
- G01R29/0871—Complete apparatus or systems; circuits, e.g. receivers or amplifiers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0864—Measuring electromagnetic field characteristics characterised by constructional or functional features
- G01R29/0892—Details related to signal analysis or treatment; presenting results, e.g. displays; measuring specific signal features other than field strength, e.g. polarisation, field modes, phase, envelope, maximum value
Abstract
The invention provides a low radiation processing system and a test method for a server management network port, and provides four radiation processing modes capable of reducing the server management network port, wherein the four modes can be used singly or optionally in one or a plurality of combinations. Through the mode, the radiation emission of the management net mouth of the server can meet the level B (the server in the industry can only reach the level A), the radiation level of the management net mouth of the server is reduced by more than 10 times compared with the radiation level of the management net mouth in the same industry, the radiation signals emitted by the management net mouth are effectively reduced, and the product performance is greatly improved. The problem of excessive radiation of a management network port is solved by adjusting the threshold resistance, the signal intensity, the switching frequency spread spectrum, the shielding network cable and the clock, so that the electromagnetic compatibility index of a product is greatly improved.
Description
Technical Field
The invention relates to the field of servers, in particular to a low-radiation processing system and a testing method for a server management network port.
Background
Electromagnetic disturbance is a serious and growing form of environmental pollution, and the influence is as little as annoying crackling sound generated during broadcast reception and as much as life accidents caused by interference of a control system. The radiation disturbance is the most important disturbance form in electromagnetic disturbance, and electromagnetic energy is directly radiated outwards in the form of electromagnetic waves, so that injury and disturbance are caused to human bodies and other equipment.
Electromagnetic radiation for managing a network interface (BMC) is a well-recognized problem in the industry, and especially under a gigabit network, a server in a shielded room and a computer in a control room are connected through a network cable, so that very strong radiation disturbance is generated.
Disclosure of Invention
In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a low-radiation processing system for a server management portal, comprising: the management network port is connected with a plurality of signal wires; a threshold resistor is provided on each signal line.
Preferably, the signal line includes: an RGMII2RXCK signal line, an RGMII2RXCTL signal line, an RGMII2RXD0 signal line, an RGMII2RXD1 signal line, an RGMII2RXD2 signal line, an RGMII2RXD3 signal line;
the threshold resistor has a resistance value ranging from 1 to 33 ohms.
Preferably, the method further comprises the following steps: a switching frequency control unit;
the switching frequency control unit includes: the device comprises a switching frequency acquisition module, a frequency decomposition module and a frequency display module;
the switching frequency acquisition module is used for acquiring the period of the management network port switching frequency spread spectrum signal and acquiring the wave peak value of each period;
the frequency decomposition module is used for decomposing the wave peak value according to a preset frequency and decomposing the wave peak value into two auxiliary wave peaks and a main wave peak; the two auxiliary wave crests are symmetrically distributed on two sides of the main wave crest; the wave peak value of the main wave peak is three quarters or one half of the wave peak value before decomposition, and the wave peak value of the main wave peak; the wave peak values of the two auxiliary wave peaks are lower than the wave peak value of the main wave peak, and the sum of the wave peak values of the two auxiliary wave peaks and the wave peak value of one main wave peak is equal to the wave peak value before decomposition;
the frequency display module is used for displaying the two auxiliary wave crests and the main wave crest which are decomposed by the frequency decomposition module on a display.
Preferably, the signal line is coated with a waterproof layer, an isolation layer, a shielding layer, a PVC inner layer, a UV layer and a PVC outer layer from inside to outside in sequence; and a silk screen layer is arranged between the shielding layer and the PVC inner layer, a silk screen layer is arranged between the PVC inner layer and the UV layer, and a silk screen layer is arranged between the UV layer and the PVC outer layer.
Preferably, the UV layer is silica nano-sized inorganic particles.
Preferably, a built-in clock chip is arranged in the management network port;
further comprising: the chip clock control module is an external clock chip connected with the management network port;
the chip clock control module is respectively connected with the internal clock chip and the external clock chip, and is used for closing the internal clock chip of the management network port and opening the external clock chip so that the external clock chip provides clock signals for the management network port.
A radiation test method for a server management network port comprises the following steps:
1) the server is arranged in an anechoic chamber, and external connection equipment of the server is connected;
2) switching on a power supply of the server and starting up the server;
3) connecting a server in a darkroom with a testing machine in a control room through a signal wire;
4) setting the IP address of the test machine and the IP address of the server management network port to be in the same network segment, and connecting the test machine and the server ping to a gigabit network;
5) in the control room, the radiation value of the server is tested by a testing machine.
According to the technical scheme, the invention has the following advantages:
the invention provides four radiation processing modes capable of reducing the management network port of the server, and the four modes can be used singly or optionally in combination. Through the mode, the radiation emission of the management net mouth of the server can meet the level B (the server in the industry can only reach the level A), the radiation level of the management net mouth of the server is reduced by more than 10 times compared with the radiation level of the management net mouth in the same industry, the radiation signals emitted by the management net mouth are effectively reduced, and the product performance is greatly improved. The problem of excessive radiation of a management network port is solved by adjusting the threshold resistance, the signal intensity, the switching frequency spread spectrum, the shielding network cable and the clock, so that the electromagnetic compatibility index of a product is greatly improved.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description will be briefly introduced, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is a schematic diagram of one embodiment of a low-emission processing system for a server management portal;
FIG. 2 is an oscillometric schematic of a switching frequency control unit;
FIG. 3 is a schematic diagram of a signal line;
fig. 4 is a flowchart of a radiation testing method for a server management portal.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of protection of this patent.
The present embodiment provides a low-radiation processing system for a server management portal, as shown in fig. 1, including: a management network port 1, a plurality of signal lines 2 connected with the management network port 1; a threshold resistance R is provided on each signal line 2.
The signal intensity of the management network port 1 is mainly controlled by the following signals: RGMII2RXCK, RGMII2 RXCLT, RGMII2RXD0, RGMII2RXD1, RGMII2RXD2 and RGMII2RXD3, the energy on the signal line can be adjusted by adjusting the resistors connected in series on the signal line, but the signals are easily greatly attenuated due to too large resistors. The signal line 2 includes: an RGMII2RXCK signal line, an RGMII2RXCTL signal line, an RGMII2RXD0 signal line, an RGMII2RXD1 signal line, an RGMII2RXD2 signal line, an RGMII2RXD3 signal line; the threshold resistor R has a resistance value in the range of 1 to 33 ohms.
In this embodiment, the system further includes: a switching frequency control unit; the switching frequency control unit includes: the device comprises a switching frequency acquisition module, a frequency decomposition module and a frequency display module; the switching frequency acquisition module is used for acquiring the period of the management network port switching frequency spread spectrum signal and acquiring the wave peak value of each period; the frequency decomposition module is used for decomposing the wave peak value according to a preset frequency and decomposing the wave peak value into two auxiliary wave peaks and a main wave peak; the two auxiliary wave crests are symmetrically distributed on two sides of the main wave crest; the wave peak value of the main wave peak is three quarters or one half of the wave peak value before decomposition, and the wave peak value of the main wave peak; the wave peak values of the two auxiliary wave peaks are lower than the wave peak value of the main wave peak, and the sum of the wave peak values of the two auxiliary wave peaks and the wave peak value of one main wave peak is equal to the wave peak value before decomposition; the frequency display module is used for displaying the two auxiliary wave crests and the main wave crest which are decomposed by the frequency decomposition module on a display.
Through analyzing a signal radiation source, the source for managing the network port radiation problem is an RGMII2RXCK signal, and a switching frequency spread spectrum technology is a popular technology for reducing circuit conduction disturbance and radiation disturbance in recent years. The difference between the switching frequency spread spectrum method and the fixed frequency method is: the frequency of the ordinary periodic signal is relatively stable, and the period of the switching frequency spread spectrum signal is changed according to a certain rule, namely, the frequency is artificially jittered.
The effect of the switching frequency spreading technique is to divide the disturbance of the equipment equally over a wide frequency spectrum, so that the EMI test is easily passed, but its disturbance energy is not changed over the whole frequency range. This method has been recognized by most regulatory agencies as a simple and easy method for devices to successfully pass electromagnetic compatibility experiments.
The switching frequency spread spectrum technique is to widen the spectral line of a periodic bandwidth signal, and to receive a part of the energy of the spectral line by using a certain condition in the measurement method, thereby obtaining a relatively small measurement value. The effect of spread spectrum techniques on the waveform of a periodic signal is frequency jitter, while the rising/falling edges of the pulses are unchanged and as steep as the original ordinary periodic signal.
The effect of spread spectrum technology is simply to make the device easy to pass electromagnetic compatibility experiments, and its disturbance energy in the whole frequency range is not changed, but rather the relatively concentrated energy is dispersed in a wider frequency band. Although the switching frequency spread spectrum method can greatly reduce the signal strength, if the signal strength is relatively strong, the energy may also be relatively strong after the spread spectrum.
Therefore, the EMI problem cannot be fundamentally solved, but it can be used as a method for solving the electromagnetic radiation emission in general. As shown in fig. 2, that is, the signal obtained by spreading the switching frequency by the switching frequency control unit.
In this embodiment, as shown in fig. 3, the signal line is sequentially wrapped with a waterproof layer 11, an isolation layer 12, a shielding layer 13, a PVC inner layer 14, a UV layer 15, and a PVC outer layer 16 from inside to outside; a silk screen layer is arranged between the shielding layer 13 and the PVC inner layer 14, a silk screen layer is arranged between the PVC inner layer 14 and the UV layer 15, and a silk screen layer is arranged between the UV layer 15 and the PVC outer layer 16. The UV layer 15 is silica nano-sized inorganic particles.
Cables are a major cause of EMI problems in the system. The EMI problem occurs in the management network port, because the server and the computer carry out signal transmission through the network cable, energy can be emitted outwards through the network cable, and if the problem that the radiation of the management network port exceeds the standard is to be solved, the cable is a key factor for solving the problem that the radiation exceeds the standard. Therefore, when the electromagnetic interference problem is encountered on the site, the problem of overproof radiation can be eliminated as long as the cable is pulled down, and the cable is proved to be an efficient receiving and radiating antenna.
One of the main methods for solving the problem of the network cable is to shield the cable, and the reason for reducing the radiation of the cable by shielding the network cable is two: one is that the shielding layer directly shields the differential mode radiation in the differential mode signal loop in the cable; another aspect is to provide a path for common mode current to return to the common mode noise source, thereby reducing the loop area of the common mode current, in a sense that the smaller the path impedance provided by the shielding layer, the better, so that most of the common mode current can be bypassed to the common mode noise source.
The key to controlling common mode radiation with shielded cables is to provide a low impedance path for common mode current to flow back to the common mode voltage source through the shielded layer. The impedance of the common mode current path provided by the network cable shielding layer is composed of two parts: one part is the impedance of the cable itself; another part is the lap resistance between the cable and the metal.
Therefore, to form a low impedance path, not only is the quality of the shielding layer of the cable itself required to be good (the radio frequency impedance is low), but also the lap joint impedance between the cable shielding layer and the metal chassis is required to be low. The method for ensuring low impedance lap joint between the cable shielding layer and the chassis is to connect the shielding layer with the chassis within 360 degrees. That is, the cable shield and the metal chassis form a complete shield, and the shield needs to be well grounded.
In this embodiment, a built-in clock chip is built in the management network port 1; the system further comprises: the chip clock control module is an external clock chip connected with the management network port; the chip clock control module is respectively connected with the internal clock chip and the external clock chip, and is used for closing the internal clock chip of the management network port and opening the external clock chip so that the external clock chip provides clock signals for the management network port.
In this embodiment, a problem is often faced that the attention to electromagnetic radiation of the machine is often limited to a certain circuit chip, and thus when the circuit board emits strong radiation, some integrated circuit chips are tried to be shielded, but the result is often disappointing. Therefore, it is necessary to know what is the main radiation source and then to administer the medicine according to the symptoms so as to completely solve the problem of electromagnetic radiation.
In the management net mouth electromagnetic radiation problem, everybody often utilizes the external mode to solve the electromagnetic radiation problem, but do not fundamentally go to know the source that electromagnetic radiation produced, the management net mouth mainly has two clock signals, one is the chip outside clock signal, one is the chip inside clock signal, wherein outside clock signal mainly plays key role to chip work, as long as there is the existence of outside clock signal, just can drive the normal work of chip, but most people are when solving the electromagnetic radiation problem, can not go the root cause that the analysis radiation produced, only take corresponding countermeasure to carry out electromagnetic radiation's filtering, ground connection, shielding, but finally do not produce good effect.
After a plurality of tests and analyses, the root of radiation generation is known to be a clock signal generated by an internal clock, so that the clock signal output is directly closed from software, and the source of radiation generation is fundamentally cut off, thereby fundamentally solving the problem of the overproof electromagnetic radiation of a management network port.
The invention provides four radiation processing modes capable of reducing the management network port of the server, and the four modes can be used singly or optionally in combination. Through the mode, the radiation emission of the management net mouth of the server can meet the level B (the server in the industry can only reach the level A), the radiation level of the management net mouth of the server is reduced by more than 10 times compared with the radiation level of the management net mouth in the same industry, the radiation signals emitted by the management net mouth are effectively reduced, and the product performance is greatly improved. The problem of excessive radiation of a management network port is solved by adjusting a threshold resistor, a signal intensity method, a switching frequency spread spectrum method, a shielding network cable method and a clock closing method, so that the electromagnetic compatibility index of a product is greatly improved.
The invention also provides a radiation test method for the server management network port, as shown in fig. 4, the test method comprises:
1) the server is arranged in an anechoic chamber, and external connection equipment of the server is connected;
2) switching on a power supply of the server and starting up the server;
3) connecting a server in a darkroom with a testing machine in a control room through a signal wire;
4) setting the IP address of the test machine and the IP address of the server management network port to be in the same network segment, and connecting the test machine and the server ping to a gigabit network;
5) in the control room, the radiation value of the server is tested by a testing machine.
According to the steps, the radiation emission condition of the server management network port can be confirmed.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (5)
1. A low-radiation processing system for managing a portal by a server, comprising: the management network port comprises a plurality of signal wires connected with the management network port and a switching frequency control unit; setting a threshold resistor on each signal line;
the switching frequency control unit includes: the device comprises a switching frequency acquisition module, a frequency decomposition module and a frequency display module;
the switching frequency acquisition module is used for acquiring the period of the management network port switching frequency spread spectrum signal and acquiring the wave peak value of each period;
the frequency decomposition module is used for decomposing the wave peak value according to a preset frequency and decomposing the wave peak value into two auxiliary wave peaks and a main wave peak; the two auxiliary wave crests are symmetrically distributed on two sides of the main wave crest; the wave peak value of the main wave peak is three quarters or one half of the wave peak value before decomposition; the wave peak values of the two auxiliary wave peaks are lower than the wave peak value of the main wave peak, and the sum of the wave peak values of the two auxiliary wave peaks and the wave peak value of one main wave peak is equal to the wave peak value before decomposition;
the frequency display module is used for displaying the two auxiliary wave crests and the main wave crest which are decomposed by the frequency decomposition module on a display.
2. The low-radiation processing system of a server management portal according to claim 1,
the signal line includes: an RGMII2RXCK signal line, an RGMII2RXCTL signal line, an RGMII2RXD0 signal line, an RGMII2RXD1 signal line, an RGMII2RXD2 signal line, an RGMII2RXD3 signal line;
the threshold resistor has a resistance value ranging from 1 to 33 ohms.
3. The low-radiation processing system of a server management portal according to claim 1,
the waterproof layer, the isolation layer, the shielding layer, the PVC inner layer, the UV layer and the PVC outer layer are sequentially wrapped outside the signal wire from inside to outside; and a silk screen layer is arranged between the shielding layer and the PVC inner layer, a silk screen layer is arranged between the PVC inner layer and the UV layer, and a silk screen layer is arranged between the UV layer and the PVC outer layer.
4. The low radiation processing system of a server management portal according to claim 3,
the UV layer is silica nano inorganic particles.
5. The low-radiation processing system of a server management portal according to claim 1,
the system further comprises: the chip clock control module is an external clock chip connected with the management network port;
a built-in clock chip is arranged in the management network port;
the chip clock control module is respectively connected with the internal clock chip and the external clock chip, and is used for closing the internal clock chip of the management network port and opening the external clock chip so that the external clock chip provides clock signals for the management network port.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1725694A (en) * | 2005-05-10 | 2006-01-25 | 杭州华为三康技术有限公司 | Network interface with filtering device |
| CN101359994A (en) * | 2008-08-30 | 2009-02-04 | 深圳华为通信技术有限公司 | Method lowering network port radiation, port impedance matching circuit and apparatus |
| CN101465766A (en) * | 2008-12-27 | 2009-06-24 | 深圳华为通信技术有限公司 | Method and device for detecting network interface radiation |
| US7609817B1 (en) * | 2005-07-05 | 2009-10-27 | Adtran, Inc. | Termination circuit for network interface unit |
| CN102226941A (en) * | 2010-09-30 | 2011-10-26 | 四川虹欧显示器件有限公司 | Control method and apparatus for electronic magnetic interference |
| CN103326794A (en) * | 2013-05-16 | 2013-09-25 | 太仓市同维电子有限公司 | Adjusting method for home gateway communication terminal failing to pass radiated emission disturbance test |
| CN103728476A (en) * | 2012-10-12 | 2014-04-16 | 天津市电力公司 | Anti-radiation interface board for electronic device testing |
| CN205376198U (en) * | 2016-02-02 | 2016-07-06 | 东风线缆集团股份有限公司 | Cable |
| CN205451752U (en) * | 2015-12-30 | 2016-08-10 | 深圳市韬略科技有限公司 | Low electromagnetic interference's display device |
-
2017
- 2017-09-07 CN CN201710800870.0A patent/CN107741531B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1725694A (en) * | 2005-05-10 | 2006-01-25 | 杭州华为三康技术有限公司 | Network interface with filtering device |
| US7609817B1 (en) * | 2005-07-05 | 2009-10-27 | Adtran, Inc. | Termination circuit for network interface unit |
| CN101359994A (en) * | 2008-08-30 | 2009-02-04 | 深圳华为通信技术有限公司 | Method lowering network port radiation, port impedance matching circuit and apparatus |
| CN101465766A (en) * | 2008-12-27 | 2009-06-24 | 深圳华为通信技术有限公司 | Method and device for detecting network interface radiation |
| CN102226941A (en) * | 2010-09-30 | 2011-10-26 | 四川虹欧显示器件有限公司 | Control method and apparatus for electronic magnetic interference |
| CN103728476A (en) * | 2012-10-12 | 2014-04-16 | 天津市电力公司 | Anti-radiation interface board for electronic device testing |
| CN103326794A (en) * | 2013-05-16 | 2013-09-25 | 太仓市同维电子有限公司 | Adjusting method for home gateway communication terminal failing to pass radiated emission disturbance test |
| CN205451752U (en) * | 2015-12-30 | 2016-08-10 | 深圳市韬略科技有限公司 | Low electromagnetic interference's display device |
| CN205376198U (en) * | 2016-02-02 | 2016-07-06 | 东风线缆集团股份有限公司 | Cable |
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