WO2016095323A1

WO2016095323A1 - Data transmission method and apparatus based on serial server

Info

Publication number: WO2016095323A1
Application number: PCT/CN2015/071529
Authority: WO
Inventors: 刘昺麟; 尹二飞
Original assignee: 北京东土科技股份有限公司
Priority date: 2014-12-16
Filing date: 2015-01-26
Publication date: 2016-06-23
Also published as: CN104486247A

Abstract

Provided are a data transmission method and apparatus based on a serial server. In the method, when receiving a data packet sent by a serial terminal, a serial server starts a timer, judges whether other data packets sent by the serial terminal are received within a timing duration of the timer, and caches the data packet and restarts the timer when the other data packets are received, or otherwise sends the cached data packet to a first far-end network device. In the embodiments of the present invention, since after receiving a data packet from a serial terminal a serial server starts a timer, when the data packet is received again within the duration range of the timer it is considered that the data packet is sent by the serial terminal, and the data packet is cached, or otherwise it is considered that the data sending process of the serial terminal ends, and accordingly the cached data packet is sent to a far-end network device, so as to recombine the cached data packet, thereby reducing the configuration requirement and resource consumption of the far-end network device, and improving the operation efficiency of the far-end network device.

Description

Data transmission method and device based on serial port server

This application claims priority to Chinese Patent Application No. 201410784390.6, entitled "A Serial Port Server-Based Data Transmission Method and Apparatus", filed on December 16, 2014, the entire contents of which are incorporated by reference. In this application.

Technical field

The present invention relates to the field of network communication technologies, and in particular, to a data transmission method and apparatus based on a serial port server.

Background technique

The serial port server is a server between the remote network device and the serial port terminal located in the Ethernet. FIG. 1 is a schematic diagram of the connection structure between the serial port server, the remote network device, and the serial port terminal. The serial port server connects the first serial port terminal and the second serial port terminal through the serial port 1 and the serial port 2 respectively, and connects to the remote network device by using a TCP connection. Only one remote network device is shown in FIG. 1 , and the serial port server can pass through A TCP connection that connects multiple remote network devices. The serial port server completes the protocol conversion between the Ethernet data and the serial port data through software. The serial port server not only expands the layout range of the device, but also makes the serial port data management more flexible and convenient.

The serial port server can realize the conversion between the serial port and the network interface, which can realize the conversion of RS-232, RS-485 and RS-422 serial port and TCP/IP network interface, thereby realizing RS-232, RS-485, RS-422. Two-way transparent transmission of serial port data and TCP/IP network interface data.

In addition, the serial server can work in TCP/UDP mode. In this mode, the serial server acts as the server and the remote network device acts as the client. The two establish a connection between the IP address and the port number to achieve bidirectional data. Transparent transmission.

When communicating based on the serial server, the remote network device connected to the serial server is undefined. When the serial terminal is a passive device, and the data sent by the serial device does not include the start and end identifiers, when the remote network device is When the serial terminal communicates, the serial server divides the received multiple consecutive responses into multiple IP packets and sends them to the remote network device. The remote network device needs to reassemble multiple IP packets. When the remote network device is In the case of a low-end network device, the low-end network device may not be able to reassemble the multiple IP packets. Even if it can be reassembled, it will consume a large amount of resources of the remote network device, thereby affecting the working efficiency of the remote network device.

Summary of the invention

In view of the above problems, the present invention has been made in order to provide a serial port server based data transmission method and apparatus that overcomes the above problems or at least partially solves the above problems.

The embodiment of the invention provides a data transmission method based on a serial port server, and the method includes:

The serial server receives the data packet sent by the serial terminal, caches the data packet, and starts a timer;

Determining whether other data packets sent by the serial terminal are received within the timer duration of the timer;

When other data packets are received, the other data packets are buffered and the timer is restarted. Otherwise, each buffered data packet is reassembled and sent to the first remote network device.

In order to effectively improve the accuracy of data transmission, in the embodiment of the present invention, the re-synthesis of each data packet that is buffered and sent to the first remote network device includes:

The serial port server determines that a timeout interrupt is generated when no other data packet is received within the timer duration of the timer;

According to the timeout interrupt, each buffered packet is reassembled and sent to the first remote network device.

In order to effectively improve the accuracy of data transmission and reduce the configuration requirements of the remote network device, after the data packet is reassembled and sent to the first remote network device, the method further includes:

The serial port server generates an identifier packet, identifies whether the data packet in the cache is reassembled, and sends the identifier packet to the first remote network device.

In order to effectively ensure the accuracy of the data transmission, determining the timing duration of the timer in the embodiment of the present invention includes:

The serial port server determines, according to each received data packet sent by the serial terminal terminal, a duration of two adjacent packet gaps;

Determining whether the lengths of the adjacent two packet gaps are equal;

When the lengths of the adjacent two packet gaps are equal, the timing duration of the timer is determined to be greater than the packet gap duration;

When the duration of the two packet gaps is not equal, and the length of the first packet gap is greater than the length of the second packet gap, it is determined that the timing duration of the timer is greater than the duration of the second packet gap is less than the duration of the first packet gap;

When the duration of the two packet gaps is not equal, and the length of the first packet gap is less than the duration of the second packet gap, it is determined that the timing duration of the timer is greater than the duration of the first packet gap is less than the duration of the second packet gap.

The serial port server receives the response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet contains redundant information, the timer duration of the timer is adjusted to be less than the current timing duration. When the response packet identifies that the reassembled data packet contains incomplete information, the timer duration is adjusted to be greater than the current timing. duration.

In order to effectively ensure the accuracy of data transmission, the method further includes:

The serial server receives the data packet sent by the serial terminal, and determines whether the current timer expires;

When the current timer expires, the data packet is sent to each remote network device connected to its TCP.

The serial server buffers the request when receiving a request sent by the second remote network device and determining that the current time is within the time duration of the timer corresponding to the first remote network device.

The embodiment of the invention provides a data transmission device based on a serial port server, and the device includes:

a receiving buffer module, configured to receive a data packet sent by the serial terminal, cache the data packet, and start a timer;

a determining module, configured to determine whether other data packets sent by the serial terminal are received within a timer duration of the timer;

The cache sending module is configured to: when the determining module determines that other data packets are received, buffer the other data packets and restart the timer; otherwise, the buffered data packets are reassembled and sent to the first remote network device.

In order to effectively improve the accuracy of the data transmission, in the embodiment of the present invention, the cache sending module is specifically configured to determine that a timeout interrupt is generated when no other data packet is received within the timer duration; and the cache is cached according to the timeout interrupt. Each packet in the packet is reassembled and sent to the first remote network device.

In order to effectively improve the accuracy of the data transmission and reduce the configuration requirements of the remote network device, the cache sending module is further configured to generate an identifier packet, identify whether the data packet in the buffer is reassembled, and send the identifier packet. Give the first remote network device.

In order to effectively ensure the accuracy of the data transmission, the device in the embodiment of the present invention further includes:

a determining module, configured to determine, according to the received each data packet sent by the serial terminal terminal, a duration of two adjacent packet gaps; determine whether the adjacent two packet gap durations are equal; When the packet gap duration is equal, the timing duration of the timer is determined to be greater than the packet gap duration; when the two packet gap durations are not equal, and the first packet gap duration is greater than the second packet gap duration, the determination is performed. The timing duration of the timer is greater than the duration of the second packet gap is less than the duration of the first packet gap; when the duration of the two packet gaps is not equal, and the length of the first packet gap is less than the duration of the second packet gap, the timing is determined. The timing duration of the device is greater than the duration of the first packet gap is less than the duration of the second packet gap.

The serial port server receives the response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet contains redundant information, the timer duration of the timer is adjusted to be less than the current timing duration. When the response packet identifies that the reassembled data packet contains incomplete information, the timer duration is adjusted to be greater than the current timing duration.

In order to ensure the accuracy of the data transmission, the determining module is further configured to: when receiving the data packet sent by the serial terminal, determine whether the current timer expires;

The cache sending module is further configured to: when the determining module determines that the current timer expires, send the data packet to each remote network device connected to the TCP.

The cache receiving module is further configured to receive a request sent by the second remote network device, in order to ensure the accuracy of the data transmission.

The determining module is further configured to determine whether it is currently located in a timing duration of a timer corresponding to the first remote network device;

The cache sending module is further configured to cache the request when the determining module determines that the current time is within a timer duration of a timer corresponding to the first remote network device.

The embodiment of the invention provides a data transmission method and device based on a serial port server. After the serial port server receives the data packet sent by the serial port terminal, the serial server starts a timer to determine whether to receive the timer within the time limit of the timer. When other data packets sent by the serial terminal are received, the data packet is buffered and the timer is restarted. Otherwise, each buffered data packet is reassembled and sent to the first remote network device. In the embodiment of the present invention, after receiving the data packet of the serial port terminal, the serial server starts a timer. When the data packet is received again within the timer duration, the data packet is considered to be sent by the serial terminal, and the data is sent. Packet buffering, otherwise the data transmission process of the serial terminal is terminated, so that the buffered data packet is reassembled and sent to the remote network device, so that the data packet in the cache is reorganized, and the configuration requirements and resources of the remote network device are reduced. Consumption increases the efficiency of the remote network device.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a schematic structural diagram of a connection between a serial port server, a remote network device, and a serial port terminal provided by the prior art;

2 is a data transmission process based on a serial port server according to an embodiment of the present invention;

FIG. 3 is a specific process of data transmission based on a serial port server according to an embodiment of the present invention:

FIG. 4 is a schematic structural diagram of a data transmission apparatus based on a serial port server according to an embodiment of the present invention.

detailed description

In order to reduce the configuration requirements and resource consumption of the remote network device and improve the working efficiency of the remote network device, the embodiment of the invention provides a data transmission method and device based on the serial port server.

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the embodiments of the present invention have been shown in the drawings, the embodiments Rather, these embodiments are provided so that this disclosure will be more fully understood and the scope of the disclosure will be fully disclosed.

The embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic diagram of a data transmission process based on a serial port server according to an embodiment of the present invention, where the process includes the following steps:

S201: The serial server receives the data packet sent by the serial terminal, caches the data packet, and starts a timer.

In the embodiment of the present invention, the serial port terminal is a passive terminal, and the remote network device sends a request to the serial port terminal through the serial port server, and after receiving the request, the serial port terminal returns a data packet to the remote network device. For this request, the serial terminal can return a data packet to the remote network device or return several data packets to the remote network device.

When the serial server receives the data packet sent by the serial terminal, in order to ensure that the data packet sent by the serial terminal is reassembled and sent to the remote network device, the serial server caches the data packet and starts a timer. The timer can be implemented in software or in hardware.

S202: Determine whether other data packets sent by the serial terminal terminal are received within the timer duration of the timer. If the determination result is yes, proceed to step S203; otherwise, proceed to step S204.

Each serial port of the serial server is connected to the corresponding serial terminal. Therefore, the serial server can determine which serial terminal sends the data packet according to the identifier of the serial port that receives the data packet.

S203: Cache the other data packet and restart the timer, and then proceed to step S202.

After receiving the other data packets sent by the serial terminal, the serial server ensures that each data packet requested by the first remote network device can be reassembled and returned. After receiving the other data packets, the serial server restarts the timer and determines that the data packet is Whether other data packets sent by the serial terminal can be received within the timer duration of the timer. In order to ensure that each packet of the serial port terminal can be reassembled, the serial server should set the timer duration longer than the packet gap length of the serial terminal to send the data packet.

S204: Reassemble each buffered packet and send it to the first remote network device.

When the data packet sent by the serial terminal is not received within the time limit of the timer, the reply process of the serial terminal is considered to be completed, and each data packet in the cache is reassembled and sent to the first remote network device.

In the embodiment of the present invention, after receiving the data packet of the serial port terminal, the serial server starts the timer. When the data packet is received again within the time limit of the timer, the data packet is considered to be sent by the serial terminal. The data packet is cached. Otherwise, the data transmission process of the serial terminal is terminated, so that the buffered data packet is sent to the remote network device, so that the data packet in the cache is reorganized, and the configuration requirements and resources of the remote network device are reduced. Consumption increases the efficiency of the remote network device.

Specifically, in the embodiment of the present invention, after the serial port server receives the data packet sent by a serial port terminal, the cache is cached. The data packet starts a timer. The timer can be a T3 timer. The timing of the T3 timer can be set as needed. The serial server determines whether other data packets sent by the serial terminal are received within the timing of the T3 timer. When receiving other data packets sent by the serial terminal, buffering the other data packets and restarting the timer, and continuing to determine Whether other data packets sent by the serial port terminal are received within the time limit of the timer; when other data packets sent by the serial port terminal are not received within the time limit of the timer, each data packet that is buffered is reassembled and sent. Give the first remote network device.

In the embodiment of the present invention, in order to ensure the integrity and accuracy of the data transmission, the serial port server receives the request sent by the second remote network device, and determines the timing of the timer currently located corresponding to the first remote network device. The request is cached for a period of time. Alternatively, when the serial server receives another request sent by the first remote network device and determines that the current timer is located within the time duration of the timer corresponding to the first remote network device, the other request is cached.

In order to effectively improve the accuracy of the data transmission, in the embodiment of the present invention, a serial port interrupt can be generated based on the serial port controller integrated by the CPU chip of the serial server, thereby realizing the combination of software and hardware, and realizing high-precision data transceiving control. The sending the buffered data packet to the first remote network device includes:

According to the timeout interrupt, the data packet in the cache is sent to the first remote network device.

When the serial server detects the timing of the timer, but does not receive other data packets sent by the serial terminal within the time limit, the serial server generates an interrupt to inform the end of the frame that the packet needs to be reorganized. Specifically, in the operating system of the serial server, after the serial port hardware (hardware) receives the data packet, the data packet is cached in the hardware cache, and the serial driver reads the data packet from the hardware cache. The data packet is transferred to the memory. When the interrupt is generated, the upper application reads the data packet from the memory and reassembles it, and sends the reassembled data packet through the network port.

Since the serial port server provides a timeout interrupt mechanism, when a timeout interrupt occurs, the serial port driver reads the data packet from the serial port hardware buffer, and puts the data packet into an identification field, identifies the data packet as data to be reassembled, and the data packet is After the memory is transferred to the memory, the upper layer application reads the data packet from the memory according to the identification field after receiving the interrupt, and reassembles the data packet and sends it.

Specifically, the serial port driver reads the data packet from the hardware buffer, and adds an identification field to the data header portion of the data packet, and then transfers the data packet to the memory. The data header of the data packet after the identifier field is added includes two parts, and the part is an identifier field. The identifier field may be, for example, one byte, for example, may be “#”, and the other part is a data length, and the data length may occupy two. Byte to identify the actual length of the data after the packet is in the data header. When the application reads the data packet from the memory, the data header portion is first read, and the length of the subsequent data can be parsed according to the information contained in the data header, so that the corresponding data content can be obtained, thereby realizing data reorganization.

The format of the data packet encapsulated by the serial server can be as shown in the following table:

Flag

Length

Data

The data header of the data packet contains an identifier flag, which identifies it as the start bit of the data packet, and the identifier can take any value, the identifier occupies one byte, and the length portion occupies two bytes, indicating The length of the actual data content starting from the fourth byte, data is the reorganized data content.

In order to facilitate the remote network device to identify each data packet, and determine whether the data packet is a reassembled data packet, after the data packet is sent to the first remote network device, in the embodiment of the disclosure, the method further includes :

Specifically, the format of the identifier packet is as follows:

Flag

Data

Time

The flag is an identifier included in the header of the identifier packet to identify the start bit of the identifier packet, and data is the actual data content of the identifier packet. The data content can only be 0 or 1. 0 indicates that the data packet has been reorganized, 1 indicates that the data packet is not reassembled, and time is the time at which the serial port server currently encapsulates the identification packet, and is mainly used to distinguish the ordinary data packet of the serial port server from the identification packet.

Determining whether the lengths of the adjacent two packet gaps are equal;

When the duration of the two packet gaps is not equal, and the length of the first packet gap is greater than the duration of the second packet gap, it is determined that the timing duration of the timer is greater than the duration of the second packet gap is less than the duration of the first packet gap.

The serial port server can flexibly set the corresponding packet gap duration for each serial port terminal according to the characteristics of each serial port terminal. Specifically, when the serial port server sets its corresponding packet gap duration for each serial port terminal, according to the serial port terminal Each data packet sent determines the length of two adjacent packet gaps of the serial terminal. For example, if the data packet sent by the serial terminal is A, B, C, ..., the time interval between the data packet A and the data packet B is the first packet gap length, and the time between the data packet B and the data packet C. The interval is the second packet gap length, and the two adjacent packet gap lengths are the first packet gap length and the second packet gap length.

After the two adjacent packet gap lengths are obtained, it is determined whether the two packet gap lengths are equal. When the two packet gap lengths are equal, the two packet gap lengths are the packet gaps corresponding to the data packets sent by the serial terminal terminal. The length, the timer duration of the timer is set to be greater than the packet gap length. Here, it is considered that the two packet gap lengths are equal, and the absolute value of the difference between the two packet gap lengths may be within a certain threshold range. When the gap lengths of the two packets are different, and the length of the first packet gap is greater than the length of the second packet gap, it indicates that the first packet gap is the packet gap after the end of the first request, and the second packet gap is the reply. The two requested packet gaps can be set to be longer than the second packet gap duration, but less than the first packet gap duration. Similarly, when the gap lengths of the two packets are different, and the first packet gap length is smaller than the second packet gap length, the first packet gap is the reply to the first requested packet gap, and the second packet gap is the reply. After the first request ends, the packet gap will be followed by another request. At this time, the timer duration can be set to be longer than the first packet gap duration, but less than the second packet gap duration.

In the embodiment of the present invention, when the remote network device has the function of determining data integrity, determining the timing duration of the timer includes:

The serial port server receives the response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet contains redundant information, adjusts the timer duration of the timer to be smaller than the current timing duration, when the response When the information contained in the packet after reassembly is incomplete, the timer duration of the timer is adjusted to be greater than the current timing duration.

Specifically, when the remote network device has the function of determining data integrity, after receiving the data packet reassembled by the serial server, the response packet may be returned to the serial server according to whether the data packet is complete. At this time, the timer duration of the timer in the serial server can be arbitrarily set. According to the set timing of the timer, it is determined that the data packet is returned to the remote network device, reassembled and sent. After receiving the reassembled data packet, the remote network device determines the integrity of the data, and the integrity information is included in the response information and sent to the serial server.

The serial server determines, according to the information contained in the response information, that the reassembled data packet contains redundant information, that is, when the reassembled data packet contains more data than the remote network device requires, determining the current timer timing time is longer. If the information of the reassembled data packet is incomplete, it is determined that the current timer has a short duration and cannot obtain complete data. It is necessary to increase the timing of the timer.

In the above manner, the interaction between the serial server and the remote network device can determine the timing of the timer corresponding to the corresponding serial terminal.

In order to effectively ensure the accuracy of data transmission in the embodiment of the present invention, the method further includes:

FIG. 3 is a specific process of data transmission based on a serial port server according to an embodiment of the present invention, where the process includes the following steps:

S301: The serial server receives the request sent by the first remote network device, and sends the request to the first serial terminal.

S302: The serial server receives the data packet returned by the first serial terminal, caches the data packet, and starts a timer.

S303: Determine whether other data packets returned by the first serial port terminal are received within the time limit of the timer. If the determination result is yes, proceed to step S304; otherwise, proceed to step S305.

S304: Cache the other data packet and restart the timer, and then proceed to step S303.

S305: Send the buffered data packet to the first remote network device.

S306: The serial server receives other data packets sent by the first serial terminal.

S307: The serial server determines whether the current timer has timed out. If the determination result is yes, proceed to step S308; otherwise, proceed to step S304.

S308: Send the data packet to each remote network device connected to its TCP.

Specifically, the serial server establishes a TCP connection with the first remote network device, and receives the request sent by the first remote network device by using the TCP connection, where the request carries the identifier information of the serial terminal that communicates with the request, and the identifier information It can be the connection address information of the serial terminal. After receiving the request, the serial server sends the request to the corresponding serial terminal. The serial terminal returns a data packet to the serial server according to the request. When the serial server receives the data packet, the data packet is buffered and a timer is started. Determining whether other data packets sent by the serial terminal are received within the time limit of the timer. When receiving other data packets sent by the serial terminal within the time limit, the other data packets are buffered and the timer is restarted. During the timer duration of the timer, it continues to monitor whether other data packets sent by the serial terminal are received. When the data packet returned by the serial terminal is not received within a certain timing of the timer, the timer is not received when the timer expires. When the data packet returned by the serial terminal is determined, it is determined that the reply process of the serial terminal ends, the data packet in the cache is reorganized, reassembled into an IP data packet, and the reassembled data packet is sent to the corresponding remote network device. .

In the embodiment of the present invention, the serial server accumulates each data packet returned by the serial terminal without timeout in a reply period, and reassembles the accumulated data packet into an IP data packet and sends it when timeout, thereby avoiding the far distance. The network device reassembles the data packet, which reduces the configuration requirements and resource consumption of the remote network device, and improves the working efficiency of the remote network device.

In addition, when the timer has expired, that is, the current timer is not activated, the serial server receives other data packets sent by the serial terminal, and the serial server sends the data packet to each remote network device connected to the TCP.

In the embodiment of the present invention, after receiving the data packet of the serial port terminal, the serial server starts a timer. When the data packet is received again within the timer duration, the data packet is considered to be sent by the serial terminal, and the data is sent. Packet buffering, otherwise it is considered that the data transmission process of the serial terminal ends, thereby transmitting the buffered data packet to the remote network device, realizing the reorganization of the data packet in the cache, and reducing the configuration requirements and resource consumption of the remote network device. Improve the efficiency of remote network devices.

FIG. 4 is a schematic structural diagram of a data transmission apparatus based on a serial port server according to an embodiment of the present invention, where the apparatus includes:

The receiving buffer module 41 is configured to receive a data packet sent by the serial terminal, cache the data packet, and start a timer.

The determining module 42 is configured to determine whether other data packets sent by the serial terminal are received within the time duration of the timer;

The buffer sending module 43 is configured to: when the determining module determines that another data packet is received, buffer the other data packet and restart the timer; otherwise, send the buffered data packet to the first remote network device.

In order to effectively improve the accuracy of the data transmission, in the embodiment of the present invention, the cache sending module 43 is specifically configured to determine that a timeout interrupt is generated when no other data packet is received within the timer duration of the timer; The data packet in the cache is sent to the first remote network device.

In order to effectively improve the accuracy of data transmission and reduce the configuration requirements of the remote network device, the cache sending module 43 is further configured to generate an identifier packet, identify whether the data packet in the buffer is reorganized, and identify the packet. Send to the first remote network device.

The determining module 44 is configured to determine, according to the received data packet sent by the serial terminal terminal, a duration of two adjacent packet gaps; determine whether the adjacent two packet gap durations are equal; When the packet gap durations are equal, the timing duration of the timer is determined to be greater than the packet gap duration; when the two packet gap durations are not equal, and the first packet gap duration is greater than the second packet gap duration, The timing duration of the timer is greater than the duration of the second packet gap is less than the length of the first packet gap; when the duration of the two packet gaps is not equal, and the length of the first packet gap is less than the duration of the second packet gap, the determining The timer duration of the timer is greater than the duration of the first packet gap is less than the duration of the second packet gap.

The device also includes:

The determining module 44 is configured to receive a response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet includes redundant information, adjust a timer duration of the timer to be less than a current timing duration. When the response packet identifies that the information contained in the reassembled data packet is incomplete, the timer duration of the timer is adjusted to be greater than the current timing duration.

In order to ensure the accuracy of the data transmission, the determining module 42 is further configured to: when receiving the data packet sent by the serial terminal, determine whether the current timer expires;

The cache sending module 43 is further configured to: when the determining module determines that the current timer expires, send the data packet to each remote network device connected to the TCP.

The cache receiving module 41 is further configured to receive a request sent by the second remote network device, in order to ensure the accuracy of the data transmission.

The determining module 42 is further configured to determine whether it is currently located in a timing duration of a timer corresponding to the first remote network device;

The cache sending module 43 is further configured to cache the request when the determining module determines that the timing of the timer currently located in the first remote network device is within a predetermined duration.

The embodiment of the invention provides a data transmission method and device based on a serial port server. After the serial port server receives the data packet sent by the serial port terminal, the serial server starts a timer to determine whether to receive the timer within the time limit of the timer. When other data packets sent by the serial terminal are received, the data packet is buffered and the timer is restarted. Otherwise, each buffered data packet is reassembled and sent to the first remote network device. In the embodiment of the present invention, after receiving the data packet of the serial port terminal, the serial server starts a timer. When the data packet is received again within the timer duration, the data packet is considered to be sent by the serial terminal, and the data is sent. Packet buffering, otherwise it is considered that the data transmission process of the serial terminal ends, thereby transmitting the buffered data packet to the remote network device, realizing the reorganization of the data packet in the cache, and reducing the configuration requirements and resource consumption of the remote network device. Improve the efficiency of remote network devices.

The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general purpose systems can also be used with the teaching based on the teachings herein. The structure required to construct such a system is apparent from the above description. Moreover, the invention is not directed to any particular programming language. It is to be understood that the invention may be embodied in a variety of programming language, and the description of the specific language has been described above in order to disclose the preferred embodiments of the invention.

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the description.

Similarly, the various features of the invention are sometimes grouped together into a single embodiment, in the above description of the exemplary embodiments of the invention, Figure, or a description of it. However, the method disclosed is not to be interpreted as reflecting the intention that the claimed invention requires more features than those recited in the claims. Rather, as the following claims reflect, inventive aspects reside in less than all features of the single embodiments disclosed herein. Therefore, the claims following the specific embodiments are hereby explicitly incorporated into the embodiments, and each of the claims as a separate embodiment of the invention.

Those skilled in the art will appreciate that the modules in the devices of the embodiments can be adaptively changed and placed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and further they may be divided into a plurality of sub-modules or sub-units or sub-components. In addition to such features and/or at least some of the processes or units being mutually exclusive, any combination of the features disclosed in the specification, including the accompanying claims, the abstract and the drawings, and any methods so disclosed, or All processes or units of the device are combined. Each feature disclosed in this specification (including the accompanying claims, the abstract and the drawings) may be replaced by alternative features that provide the same, equivalent or similar purpose.

In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features that are included in other embodiments and not in other features, combinations of features of different embodiments are intended to be within the scope of the present invention. Different embodiments are formed and formed. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

The various component embodiments of the present invention may be implemented in hardware, or in a software module running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components of a serial server based data transmission device in accordance with embodiments of the present invention. . The invention can also be implemented as a device or device program (e.g., a computer program and a computer program product) for performing some or all of the methods described herein. Such a program implementing the invention may be stored on a computer readable medium or may be in the form of one or more signals. Such signals may be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

It is to be noted that the above-described embodiments are illustrative of the invention and are not intended to be limiting, and that the invention may be devised without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as a limitation. The word "comprising" does not exclude the presence of the elements or steps that are not recited in the claims. The word "a" or "an" The invention can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means can be embodied by the same hardware item. The use of the words first, second, and third does not indicate any order. These words can be interpreted as names.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

A serial port server based data transmission method, characterized in that the method comprises:

The serial server receives the data packet sent by the serial terminal, caches the data packet, and starts a timer;

Determining whether other data packets sent by the serial terminal are received within the timer duration of the timer;

When other data packets are received, the other data packets are buffered and the timer is restarted. Otherwise, each buffered data packet is reassembled and sent to the first remote network device.
The method of claim 1, wherein the reassembling each of the cached data packets and transmitting the data to the first remote network device comprises:

The serial port server determines that a timeout interrupt is generated when no other data packet is received within the timer duration of the timer;

According to the timeout interrupt, each buffered packet is reassembled and sent to the first remote network device.
The method according to claim 1 or 2, wherein after the reassembling each of the cached data packets and transmitting the data to the first remote network device, the method further includes:

The serial port server generates an identifier packet, identifies whether the data packet in the cache is reassembled, and sends the identifier packet to the first remote network device.
The method of claim 1 wherein determining the timing duration of the timer comprises:

The serial port server determines, according to each received data packet sent by the serial terminal terminal, a duration of two adjacent packet gaps;

Determining whether the lengths of the adjacent two packet gaps are equal;

When the lengths of the adjacent two packet gaps are equal, the timing duration of the timer is determined to be greater than the packet gap duration;

When the duration of the two packet gaps is not equal, and the length of the first packet gap is greater than the length of the second packet gap, it is determined that the timing duration of the timer is greater than the duration of the second packet gap is less than the duration of the first packet gap;

When the duration of the two packet gaps is not equal, and the length of the first packet gap is less than the duration of the second packet gap, it is determined that the timing duration of the timer is greater than the duration of the first packet gap is less than the duration of the second packet gap.
The method of claim 1 wherein determining the timing duration of the timer comprises:

The serial port server receives the response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet contains redundant information, the timer duration of the timer is adjusted to be less than the current timing duration. When the response packet identifies that the reassembled data packet contains incomplete information, the timer duration is adjusted to be greater than the current timing duration.
The method of claim 1 wherein the method further comprises:

The serial port server receives the data packet sent by the serial port terminal, and determines whether the current timer expires;

When the current timer expires, the data packet is sent to each remote network device connected to its TCP.
The method of claim 1 wherein the method further comprises:

The serial server buffers the request when receiving a request sent by the second remote network device and determining that the current time is within the time duration of the timer corresponding to the first remote network device.
A serial port server-based data transmission device, characterized in that the device comprises:

a receiving buffer module, configured to receive a data packet sent by the serial terminal, cache the data packet, and start a timer;

a determining module, configured to determine whether other data packets sent by the serial terminal are received within a timer duration of the timer;

The cache sending module is configured to: when the determining module determines that other data packets are received, buffer the other data packets and restart the timer; otherwise, the buffered data packets are reassembled and sent to the first remote network device.
The device according to claim 8, wherein the buffer sending module is configured to: determine that a timeout interrupt is generated when no other data packet is received within a timer duration; and each cache is buffered according to a timeout interrupt The data packets are reassembled and sent to the first remote network device.
The device according to claim 8 or 9, wherein the buffer sending module is further configured to generate an identifier packet, identify whether the data packet in the buffer is reorganized, and send the identifier packet to the first far End network equipment.
The device of claim 8 further comprising:

a determining module, configured to determine, according to the received each data packet sent by the serial terminal terminal, a duration of two adjacent packet gaps; determine whether the adjacent two packet gap durations are equal; When the packet gap duration is equal, the timing duration of the timer is determined to be greater than the packet gap duration; when the two packet gap durations are not equal, and the first packet gap duration is greater than the second packet gap duration, the determination is performed. The timing duration of the timer is greater than the duration of the second packet gap is less than the duration of the first packet gap; when the duration of the two packet gaps is not equal, and the length of the first packet gap is less than the duration of the second packet gap, the timing is determined. The timing duration of the device is greater than the duration of the first packet gap is less than the duration of the second packet gap.
The device of claim 8 further comprising:

a determining module, configured to receive a response packet returned by the first remote network device, and when the response packet identifies that the reassembled data packet includes redundant information, adjust a timer duration of the timer to be less than a current timing duration. When the response packet identifies that the information contained in the reassembled data packet is incomplete, the timer duration of the timer is adjusted to be greater than the current timing duration.
The device according to claim 8, wherein the determining module is further configured to: when receiving the data packet sent by the serial terminal, determine whether the current timer expires;

The cache sending module is further configured to: when the determining module determines that the current timer expires, send the data packet to each remote network device connected to the TCP.
The device according to claim 8, wherein the buffer receiving module is further configured to receive a request sent by the second remote network device;

The determining module is further configured to determine whether a timer that is currently located corresponding to the first remote network device is determined Within a period of time;

The cache sending module is further configured to cache the request when the determining module determines that the current time is within a timer duration of a timer corresponding to the first remote network device.