CN104104647B - Connection maintaining method - Google Patents

Abstract

The present invention provides a method for maintaining a connection, which is used to maintain the connection status between an electronic device and a server. The method includes the following steps: (a) sending an Nth test packet to a server, wherein the Nth test packet requires the server to respond to the electronic device after waiting for N intervals; (b) determining whether a response to the Nth test packet sent by the server is received; (c) if so, repeating step (a); if not, calculating the time from sending the N-1th test packet to receiving the server response as the cycle time; and (d) when the electronic device is switched to a standby/sleep mode, sending a maintenance packet to the server according to the cycle time to maintain the connection status with the server. Through the design of the present invention, the electronic device can maintain the connection status with the server while reducing resource consumption.

Description

Stay Alive Method

technical field

The invention relates to a method for maintaining a connection, in particular to a method for maintaining a connection between an electronic device and a server.

Background technique

Generally, if a user wants to connect to each other through a computer and a remote server, a connection path must be established through the network and related equipment (such as a router or a sharer, etc.). In the past, computers used fixed IP. Even if the connection between the computer and the server was interrupted, the server could find the corresponding connected computer through their independent fixed IP addresses; however, most computers use floating (virtual) IP nowadays. If the computer does not send a packet to the server for a certain period of time, the router in the connection path may close the communication port used by the computer, so that the server cannot find the IP address used by the corresponding computer, which will result in a connection between the computer and the server interruption. At this time, the client computer must actively re-establish a connection with the server in order to restore the previous connection state. Therefore, when the computer is in some specific mode (such as hibernation or standby mode), in order to maintain the connection between the two, the computer must periodically send packets to the server.

If the above-mentioned computer sends packets too frequently, it will cause unnecessary consumption of computer resources; and if the interval between sending packets is too long, it will cause the connection with the server to be interrupted. In addition, the connection path between the computer and the server often needs to be connected through multiple routers. The setting time for closing the communication port of each router is different. Therefore, how to determine the optimal interval for the computer to send packets is a practical It is a subject worth studying.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method for maintaining a connection between an electronic device and a server, so as to solve the problem that the electronic device in the prior art is easily disconnected from the server due to being idle for too long. technical issues.

To achieve the above objectives, the connection maintenance method of the present invention is used to maintain the connection status between the electronic device and the server. The method includes the following steps: (a) sending the Nth test packet to the server, and the Nth test packet requires the server to wait for an interval of N intervals before responding to the electronic device, where N is a positive integer; (b) judging whether the packet is received The response sent by the server to the Nth test packet; (c) if yes, repeat step (a); if not, calculate the period time elapsed from sending the N-1th test packet to receiving the server response; and (d) When the electronic device switches to the standby/sleep mode, it sends a maintenance packet to the server according to the cycle time, so as to maintain the connection state with the server.

In another embodiment of the present invention, the method for maintaining connection of the present invention includes the following steps: (a) sending the Nth test packet to the server, and the Nth test packet requires the server to wait for an interval of N intervals before responding to the electronic device, where N is a positive integer; (b) judging whether the response sent by the server to the Nth test packet is received; (c) if the response sent by the server to the Nth test packet is received, repeat the step (a ); if the response sent by the server to the Nth test packet is not received, it will repeatedly send the N-1th test packet and judge whether it has received the response from the server to all the N-1th test packets; (d) If you receive the server's response to all the repeated N-1 test packets, calculate the time elapsed from sending the N-1 test packet to receiving the server's response as the cycle time; For the response of the N-1th test packet, the time elapsed from sending the N-2th test packet to receiving the server response is calculated as the cycle time; and (e) when the electronic device switches to the standby/sleep mode, according to the cycle time Time to send a maintenance packet to the server to maintain the connection status with the server.

Through the design of the present invention, it is possible to find a more suitable packet sending period for the electronic device to the server, on the one hand, it can maintain the connection state between the electronic device and the server in the standby/sleep mode, and avoid connection interruption; on the other hand, Then, the packet sending cycle is extended as much as possible in the allowed state, so as to reduce resource consumption of the electronic device itself.

Description of drawings

Fig. 1 is the schematic diagram that each electronic device of the present invention and server are connected through network;

Fig. 2 is a system block diagram of the electronic device of the present invention;

FIG. 3 is a flow chart of the first embodiment of the method for maintaining connection of the present invention;

FIG. 4 is a flow chart of the second embodiment of the connection maintenance method of the present invention.

reference sign

10a: First electronic device 10b: Second electronic device

11: System module 12: Transmission module

13: Test Module 20: Server

30: Network 31: Internet

32: LAN A, B, C, D, E, F: Router

P1, P2: connection path

Detailed ways

In order to understand the technical content of the present invention, the preferred embodiments are given and described as follows.

In one embodiment of the present invention, the electronic device can be a computer device, a portable electronic device, or other electronic devices with network connection functions, etc., and the server is a general server host or a similar device that can provide server functions, but The present invention is not limited thereto.

Please refer to FIG. 1 , which is a schematic diagram of the connection between the electronic devices and the server 20 through the network 30 of the present invention. As shown in FIG. 1, the first electronic device 10a and the second electronic device 10b are connected to the server 20 through the network 30, and a plurality of routers (routers) A~F are included in the network 30 environment, so that the first electronic device 10a and the second electronic device 10b respectively form connection paths with the server 20 through different routers according to their locations. For example, the first electronic device 10a can be connected to the server 20 through the routers A, D, and F in the Internet 31, which constitute the connection path P1; and the second electronic device 10b can be connected to the server 20 through the routers B, C and the routers E and F in the Internet 31 are connected to the server 20, which constitute different connection paths P2.

Please refer to FIG. 2 which is a system block diagram of the first electronic device 10a or the second electronic device 10b of the present invention. As shown in FIG. 2 , the first electronic device 10 a or the second electronic device 10 b of the present invention may include a system module 11 , a transmission module 12 and a test module 13 . The system module 11 can be at least one or a combination of hardware, software and firmware, for example, the system module 11 can be a central processing unit, or the integration of the central processing unit and the operating system in the device, etc., but the present invention is not limited thereto . The system module 11 can switch the first electronic device 10a or the second electronic device 10b into the normal operation mode or the standby/sleep mode according to the user's instruction or setting, and execute various operation commands; and in the standby/sleep mode, The system module 11 will continuously generate a maintenance packet and send it to the server through the transmission module 12 to maintain the connection status with the server. The transmission module 12 is used for sending a packet to the server or receiving a response packet from the server, where the transmission module 12 can be a single network processing chip or a combination of a transmission port.

The test module 13 is used to generate different test packets to be sent to the server through the transmission module 12; and the test module 13 judges whether the server responds to each test packet, so as to dynamically determine the optimal sending period of the aforementioned maintenance packets. In an embodiment of the present invention, the testing module 13 can be an application program, but it can also be combined with hardware or firmware to perform the same function, which is not limited to this embodiment. The aforementioned test packet may be a user datagram protocol (UDP) packet.

It is worth mentioning that, for electronic devices that need to be connected to routers through network access points (Access Points, APs), in addition to maintaining the connection status with these routers, the electronic devices also need to maintain a connection with the routers. The connection status between network accessors to avoid network interruption. The network access device will send packets to the electronic device connected to it from time to time, and the electronic device will rely on the driver and firmware of its own network card (such as the aforementioned transmission module 12) to process these packets and respond to the network The access device maintains the connection between the electronic device and the network access device. On the premise that the electronic device is connected to the network access device, the electronic device can send the test packet to the server through the routers. Since the technology of maintaining the connection between the electronic device and the network access device belongs to the prior art, it will not be repeated here.

Please refer to FIG. 3 , which is a flow chart of a first embodiment of the connection maintenance method of the present invention. It should be noted that, although the first electronic device 10a and its connection path P1 with the server 20 shown in FIGS. This is limited, and should be changed according to the structure of the electronic device or its connection path with the server 20 . As shown in FIG. 3 , the connection maintenance method of the present invention includes steps S301 to S304 . Each step of the method will be described in detail below.

Step S301: Send an Nth test packet to the server 20, wherein the Nth test packet requires the server 20 to wait for N intervals before responding to the electronic device, and N is a positive integer.

When the first electronic device 10a is still in the normal operation mode, the test module 13 can send one or more test packets to the server 20 through the transmission module 12, wherein the first test packet will require the server 20 to wait for an interval , and then transmit the response to the first test packet to the first electronic device 10a; here, the interval time is the default value of the test module 13 or the time value set by the user, which can range from several seconds to tens of seconds. When the first electronic device 10a sends the second test packet, the second test packet will require the server 20 to wait for 2 intervals (ie interval*2) before sending a response to the second test packet to the second An electronic device 10a; and so on for the sent Nth test packet, requiring the server 20 to wait for N intervals before responding to the first electronic device 10a, where N is a positive integer.

For example, assuming that the set interval time is 5 seconds, the first test packet sent by the first electronic device 10a will require the server 20 to wait for an interval of 5 seconds before sending the first test packet after receiving the packet. response packet; if the first electronic device 10a sends the second test packet, the server 20 is required to wait for 10 seconds (that is, two 5-second intervals) after receiving the packet, and then send a response to the second test packet packets, and so on.

Step S302: Determine whether the response sent by the server 20 to the Nth test packet is received.

In theory, when the first electronic device 10a is connected to the server 20, the server 20 will respond to the packet of the first electronic device 10a; if the connection between the first electronic device 10a and the server 20 is interrupted, the server 20 will send The response packet of will not be successfully transmitted to the first electronic device 10a. Therefore, when the test module 13 of the first electronic device 10a sends the Nth test packet to the server 20, the test module 13 will determine whether the test packet has received the response sent by the server 20 to the test packet to determine It continues with the steps.

In one embodiment of the present invention, the test module 13 judges whether the response time of the server 20 exceeds the sum of the N section intervals corresponding to the round-trip time of a packet, as a result of judging whether the response from the server 20 is received. The standard of the response sent by the Nth test packet, but the present invention is not limited thereto. The so-called packet round-trip time here is the total time for the receiving server 20 to respond to the packet immediately after the first electronic device 10a sends a packet to the server 20; The total round-trip time from when the device 10a sends a packet to when it receives a response to the packet. The round-trip time of the packet plus the sum of the N intervals corresponding to the test packet is the theoretical total time from sending the test packet to receiving a response to the test packet.

If the test module 13 receives the response sent by the server 20 to the test packet, it means that the server 20 can still maintain the connection between the first electronic device 10a and the server 20 after waiting for the N intervals corresponding to the test packet. The line path is not interrupted, so consider increasing the waiting interval to find the best keep-alive packet sending cycle. At this time, the test module 13 will return to step S301 to send the next test packet.

Step S303: Calculate the elapsed time from sending the N-1th test packet to receiving the response from the server 20 as a cycle time.

If the test module 13 fails to receive the response sent by the server 20 to the Nth test packet, it means that the server 20 waits for the N segment interval time corresponding to the test packet, and the communication between the first electronic device 10a and the server 20 The connection may have been interrupted, so consider going back to the previous test packet (i.e. the N-1th test packet), and calculate the elapsed time from the first electronic device 10a sending the N-1th test packet to the receiving server 20’s response, and use it as a cycle time. Wherein, in the state of N=1, if no response from the server to the first test packet is received, the round-trip time of the aforementioned packet in the normal state is taken as the cycle time.

Step S304: After the electronic device switches to the standby/sleep mode, send a maintenance packet to the server 20 according to the cycle time, so as to maintain the connection state with the server 20 .

After the cycle time is determined, the test module 13 can notify the system module 11; and when the first electronic device 10a switches to the standby/sleep mode, the system module 11 will continue and periodically send maintenance packets to the server 20 at this cycle time to Keep connected with the server 20.

An implementation is given below to describe how to apply the first embodiment of the connection maintenance method of the present invention. Table 1 shows the hypothetical value of the waiting time for each router A-F to close its communication port in FIG. 1; Table 2 shows the connection status between the first electronic device 10a and the server 20 by applying the first embodiment of the connection maintenance method of the present invention The result of the test.

Table 1

router A B C D. E. f wait time (seconds) 50 60 90 32 40 70

Table 2 (first electronic device 10a)

As shown in Table 1, each router A-F will set a waiting time for closing its communication port. When the communication port that the router is originally using has no packet passing through after the set waiting time, the router will automatically close the communication port to end the original use status, so that the communication port can be used by other devices for connection. Due to the differences in the brand and specification design of each router A~F, each router A~F has a different waiting time; in reality, it is impossible to know exactly the waiting time of each router A~F, so these The waiting time is a hypothetical value and is not limited to what is shown in Table 1.

As shown in Table 2, in this embodiment, the first electronic device 10a is connected to the server 20 via the connection path P1, assuming that each interval is 5 seconds, and because the aforementioned packet round-trip time is usually very short, in this embodiment In the method, for the convenience of explanation, it is assumed that the round-trip time of the packet is 0 seconds, so the elapsed time from the first electronic device 10a sending the Nth test packet to the receiving server 20 responding to the packet is roughly equal to the N time corresponding to the Nth test packet. interval, but the present invention is not limited thereto.

Please refer to Figure 1, Figure 2, Table 1 and Table 2 together. When the first electronic device 10a applies the first embodiment of the method for maintaining connection of the present invention, first the first electronic device 10a will send the first test packet to the server 20, and the first test packet requires the server 20 to wait for an interval of 5 seconds After a time, send a response packet to the first electronic device 10a; since the interval time is less than the waiting time of each router A, D, and F in the connection path P1, it means that the server 20 can successfully send the response of the first test packet The packet is sent to the first electronic device 10a, so that the first electronic device 10a can continue to send the next test packet. Although the 2nd to 6th test packets sent subsequently add up the 5-second interval time one by one, the 6-segment interval time corresponding to the 6th test packet (that is, the 30-second interval time) is also shorter than the routers A, D, and F. The waiting time indicates that the server 20 can successfully send the response packets of the second to sixth test packets to the first electronic device 10a.

Then, when the first electronic device 10a sent the 7th test packet to the server 20, the 35-second interval time that the 7th test packet required the server 20 to wait was greater than the 30-second wait time of the router D in the connection path P1; so that the server 20. During the process of sending the response packet of the seventh test packet to the first electronic device 10a, because the communication port of the router D connected to the router A has been closed and the connection is interrupted, it cannot be successfully transmitted to the first electronic device 10a. After the test module 13 of the first electronic device 10a judges that it has not received the response packet sent by the server 20 for the 7th test packet, it knows that the 35-second interval is too long, so the test module 13 will go back to the previous 6th test packet. The status of the second test packet is taken as the cycle time from sending the sixth test packet to receiving the response from the server 20 (30 seconds in this embodiment). Then when the first electronic device 10a switches to the standby/sleep mode, the system module 11 sends a maintenance packet to the server 20 every 30 seconds to maintain the connection status between the first electronic device 10a and the server 20 .

Please refer to FIG. 4 , which is a flow chart of a second embodiment of the connection maintenance method of the present invention. It should be noted that although the electronic device 10b and its connection path P2 with the server 20 shown in FIGS. The limit should be changed according to the structure of the electronic device or its connection path with the server 20 . As shown in FIG. 4 , the second embodiment of the method for maintaining connection of the present invention includes steps S401 to S406 , wherein steps S401 and S402 are the same as steps S301 and S302 of the first embodiment, and will not be repeated here. Each newly added step of the method will be described in detail below.

Step S401: Send an Nth test packet to the server 20, wherein the Nth test packet requires the server 20 to wait for N intervals before responding to the electronic device 10b, and N is a positive integer.

Step S402: Determine whether the response sent by the server 20 to the Nth test packet is received.

If the test module 13 receives the response sent by the server 20 to the test packet, the test module 13 will return to step S401 to send the next test packet.

Step S403 : Repeatedly send the N-1th test packet to the server 20 .

If the test module 13 fails to receive the response sent by the server 20 to the Nth test packet, it means that the server 20 waits for the N interval corresponding to the test packet, and the second electronic device 10b and the server 20 The connection may have been broken, so consider going back to the previous test packet (ie, the N-1th test packet). In order to avoid that the elapsed time from sending the N-1th test packet to the server responding to the packet may be close to the waiting time of a certain router, resulting in unstable connection status, at this time only a single test may not be able to reflect the status quo; therefore, the test The module 13 will repeatedly send the N-1th test packet to the receiving server 20 for multiple times. In this embodiment, the test module 13 will repeatedly send the N-1th test packet to the server 20 at least 3 times, and the number of times can be adjusted according to design needs.

Step S404: Determine whether the responses sent by the server 20 to all the N-1th test packets are received.

After the test module 13 repeatedly sends the N-1th test packets to the receiving server 20, it will determine whether the server 20 has received the responses sent by the server 20 to all the N-1th test packets. If the test module 13 confirms that the N-1th test packet sent each time will receive a response, then proceed to step S405; if the test module 13 confirms that the N-1th test packet sent each time will not receive a response, Then go to step S406.

Step S405: Calculate the elapsed time from sending the N-1th test packet to receiving the response from the server 20 as a cycle time.

If the test module 13 receives the response from the server 20 to all the N-1th test packets sent by the server 20, it means that the server 20 sends the N-1th test packet from the second electronic device 10b to the server 20. The elapsed time should be less than The waiting time of each router, that is, the connection is stable in this state, so calculate the elapsed time from the first electronic device 10a sending the N-1th test packet to receiving the response from the server 20, and use it as the cycle time.

Step S406: Calculate the elapsed time from sending the N-2th test packet to receiving the server response last time as a cycle time.

If the test module 13 fails to receive the response of the server 20 to all the N-1 test packets sent, it means that the N-1 section interval time corresponding to the N-1 test packet may be close to the waiting time of a certain router; In the state where the network transmission processing is delayed, the time error caused by it plus the N-1 interval time will be greater than the waiting time of a certain router, which will cause the connection between the second electronic device 10b and the server 20 to be interrupted, The connection status is also relatively unstable. Therefore, the test module 13 considers going back to the previous test packet (i.e. the N-2th test packet), calculates the elapsed time from the second electronic device 10b sending the N-2th test packet to the receiving server 20 response, and Use it as cycle time.

Step S407 is also included after step S405 or step S406: when the electronic device switches to the standby/sleep mode, send a maintenance packet to the server 20 according to the cycle time, so as to maintain the connection state with the server 20 .

After the cycle time is determined, the test module 13 can notify the system module 11 that when the second electronic device 10b switches to the standby/sleep mode, it will continue and regularly send maintenance packets to the server with the cycle time calculated in step S405 or step S406 20, to keep the connection state with the server 20.

Hereinafter, another implementation mode is given to illustrate how to apply the second embodiment of the method for maintaining connection of the present invention. Table 3 shows the results of the connection status test performed by the second electronic device 10b and the server 20 by applying the second embodiment of the connection maintenance method of the present invention.

Table 3 (second electronic device 10b)

As shown in Table 3, in this embodiment, the second electronic device 10b is connected to the server 20 via the connection path P2, assuming that each interval is 5 seconds, and because the aforementioned packet round-trip time is usually very short, in this embodiment In the method, for the convenience of explanation, it is assumed that the round-trip time of the packet is 0 seconds, so the elapsed time from the second electronic device 10b sending the Nth test packet to the receiving server 20 responding to the packet is roughly equal to the Nth time corresponding to the Nth test packet. interval, but the present invention is not limited thereto.

Please refer to Figure 1, Figure 2, Table 1 and Table 3 together. When the second electronic device 10b uses the first embodiment of the method for maintaining connection of the present invention, first the second electronic device 10b will send the first test packet to the server 20, and the first test packet requires the server 20 to wait for an interval of 5 seconds After a certain time, send a response packet to the second electronic device 10b; since the interval time is less than the waiting time of each router B, C, E, and F in the connection path P1, it means that the server 20 can successfully send the first test packet The response packet is sent to the second electronic device 10b, so that the second electronic device 10b can continue to send the next test packet. Although the 2nd to 7th test packets sent subsequently add up the 5-second interval time one by one, the 7-segment interval time corresponding to the 7th test packet (that is, the 35-second interval time) is also shorter than the routers B, C, E, The waiting time of F indicates that the server 20 can successfully send the response packets of the second to seventh test packets to the second electronic device 10b.

Next, when the second electronic device 10b sends the eighth test packet to the server 20, the eighth test packet requires the server 20 to wait for an interval of 40 seconds approximately equal to the 40-second waiting time of the router E in the connection path P2. When the server 20 sends the response packet of the eighth test packet to the second electronic device 10b, if the network status is stable, it is still possible to complete the transmission of the response packet before the communication port of the router E is closed. At this time, the second electronic device 10b can continue to send the ninth test packet; if the network status is unstable and the transmission delay is caused, the communication port of the router E may be closed first and the connection is interrupted, and the response packet cannot be successfully transmitted to the second electronic device 10b. At this time, it is the same as the method of the aforementioned first embodiment, going back to the previous 7th test packet, and taking the elapsed time from sending the 7th test packet to receiving the response from the server 20 as the cycle time. In this embodiment, it is temporarily assumed that the network status is relatively stable, so that the second electronic device 10b can continue to send the ninth test packet.

When the second electronic device 10b sent the ninth test packet to the server 20, the ninth test packet required the server 20 to wait for an interval of 45 seconds greater than the 40-second waiting time of the router E in the connection path P2; so that the server 20 sent During the process of sending the response packet of the ninth test packet to the second electronic device 10b, because the communication port of the router E connected to the router C has been closed and the connection is interrupted, it cannot be successfully transmitted to the second electronic device 10b. After the test module 13 of the second electronic device 10b judges that the response packet sent by the server 20 for the 9th test packet has not been received, it judges that the 45-second interval is too long, so the test module 13 will go back to the previous 8th test packet. The status of the test packet.

However, in this embodiment, in order to ensure that the second electronic device 10b can normally receive the response packet (that is, the connection between the second electronic device 10b and the server 20 is stable and uninterrupted), the test module 13 will repeatedly send at least three times The 8th test packet. Assuming that the second electronic device 10b can receive all the response packets of the eighth test packet sent, it means that the corresponding 8 intervals (that is, the interval of 40 seconds) are appropriate, so the second electronic device 10b can automatically The elapsed time (40 seconds in this embodiment) from sending the eighth test packet to receiving the response from the server 20 is the cycle time.

If it is assumed that the second electronic device 10b has not received all the response packets sent by the eighth test packet, it means that the elapsed time from sending the eighth test packet to receiving the response from the server 20 may still be greater than the waiting time of the router. The line is interrupted, so the second electronic device 10b will go back to the previous 7th test packet, and take the elapsed time (35 seconds in this embodiment) from sending the 7th test packet to receiving the response from the server 20 as the cycle time.

Through the design of the present invention, the electronic device finds a more appropriate cycle time within the maximum allowable range, and periodically sends maintenance packets to the connection server after switching to the standby/sleep mode, so as to maintain the connection state with the server In this way, when necessary, the server can remotely wake up the electronic device at any time through the network to perform operations such as data access. At the same time, the design of the present invention can greatly reduce the times of packet transmission, so as to save resource consumption of the electronic device.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should all belong to the scope of protection of the appended claims of the present invention.

Claims (9)

1. one kind maintains bus connection method, for maintaining the connection state between an electronic installation and a server, it is characterised in that This method comprises the following steps：

(a) sending a n-th test packets to the server, wherein n-th test packets requires the server in wait N sections The electronic installation is responded after interval time again, and N is positive integer；

(b) judge whether to receive the response that the server sends the n-th test packets；

If the response that the server is sent to the n-th test packets (c) is received, repeat step (a)；If do not receive The response that the server is sent to the n-th test packets, then calculate previous from the N-1 times test packets are sent to reception The server responds institute's elapsed time to be directly set as a cycle time；And

(d) after the electronic installation switches to a standby/park mode, send one according to the cycle time and maintain package to the clothes Business device, to maintain the connection state between the server.

2. maintenance bus connection method according to claim 1, it is characterised in that judge to wait the server in step (b) Whether the time of response adds the summation of N section interval times more than a package turnaround time, and the package turnaround time is from the electricity After sub-device sends a package to the server, the total time that the server responds to the package immediately is received.

3. maintenance bus connection method according to claim 2, it is characterised in that in the state of N=1, if not receiving this The response that server is sent to the 1st test packets, then using the package turnaround time as a cycle time.

4. maintenance bus connection method according to claim 1, it is characterised in that the interval time is 5~20 seconds.

5. one kind maintains bus connection method, for maintaining the connection state between an electronic installation and a server, it is characterised in that This method comprises the following steps：

(a) sending a n-th test packets to the server, wherein n-th test packets requires the server in wait N sections The electronic installation is responded after interval time again, and N is positive integer；

(b) judge whether to receive the response that the server sends the n-th test packets；

If the response that the server is sent to the n-th test packets (c) is received, repeat step (a)；If do not receive The response that the server is sent to the n-th test packets, then the N-1 times test packets are sent repeatedly and judge whether to connect Receive the response that the server is sent to all the N-1 times test packets；

If (d) receiving response of the server to all the N-1 times test packets sent repeatedly, calculate and send this certainly The N-1 times test packets is a cycle time to server response institute's elapsed time is received；If the server pair is not received The response of all the N-1 times test packets sent repeatedly, then calculate previous from the N-2 times test packets are sent to reception The server responds institute's elapsed time to be directly set as a cycle time；And

(e) after the electronic installation switches to a standby/park mode, send one according to the cycle time and maintain package to the clothes Business device, to maintain the connection state between the server.

6. maintenance bus connection method according to claim 5, it is characterised in that at least 3 N- are sent in step (c) 1 test packets is to the server.

7. maintenance bus connection method according to claim 5, it is characterised in that judge to wait the server in step (b) Whether the time of response exceedes responds the envelope from the electronic installation one package of transmission in the case of not postponing to the server is received One turnaround time of bag, plus the summation of N section interval times.

8. maintenance bus connection method according to claim 7, it is characterised in that in the state of N=1, if not receiving this The response that server is sent to the 1st test packets, then using the turnaround time as a cycle time.

9. maintenance bus connection method according to claim 5, it is characterised in that the interval time is 5~20 seconds.