1.1 Working principle of remote control software

Remote control must be carried out through the network. Located in the local computer is to manipulate the end of the command, called the master or client, non-local controlled computer is called the controlled end or server. "Remote" is not the same as long distance, the master and the controlled end can be located in the same room of the same LAN, can also be connected to the Internet in any location of the two or more computers.

Remote control software is generally divided into two parts: one part is the client program Client, the other part is the server-side program Server (or Systry), in the use of the client program before the need to install the master computer, the server-side program installed on the computer to be controlled. The process of its control is to execute the Client program on the master computer first, like an ordinary client to send signals to the server-side program in the controlled computer to establish a special remote service, and then through this remote service, use the remote control function to send remote control commands to control the operation of various applications in the controlled computer, which is a remote control method based on remote service. This remote control method is remote control based on remote service.

This remote control method is called remote control based on remote service. What I said before is the case of one computer to one computer, in fact, the most suitable mode for remote control based on remote service is one to many. That is, using remote control software pcAnywhere, weighing and dosing system using the advantages of LAN to use one computer to control multiple computers to realize remote multi-point control. In carrying out control of one computer to multiple remote computers, the remote control software is like a network administrator of a LAN, and the remote terminal service providing remote control is like an extension of the office LAN. This one-to-many connection saves network resources while making network access safer and more reliable, and it is easier for the network administrator to manage each computer on the LAN.

1.2 Basic Principle of Remote Wakeup

When you want to wake up a computer, according to each network card has its own unique MAC address to identify the computer. That is, in the local computer to run the remote wake-up software, to the network to send with the MAC address of the network card with a special "Wake-up" packet, the wake-up computer to confirm that the data is sent to their own, through the three-core cable to the computer to send out the boot signal.

2 The necessity of remote control and remote wakeup

Weighing loading system and feeding system after several years of input and improvement, formed a huge network system, which has the following characteristics:

(1) The measuring network system covers a wide range;

(2) The computers at the controlled end are all far away from the computer at the main control end;

(3) When the controlled end of the computer program can not run normally, the fault must be handled in a timely manner, otherwise it will have an impact on the production or measurement data settlement;

(4) Sometimes the cause of failure is relatively simple, and the time spent on troubleshooting is much shorter than the time spent on the road. With the development of information technology, in order to improve our management level, in order to complete all the work in a more timely, efficient and perfect way, we have adopted remote control technology.

In the process of network operation, the normal operation of the computer at the controlled end cannot be guaranteed because the passive end is sometimes susceptible to power outages or man-made conditions. The remote control of the weighing and dosage system has no operator at the controlled end, but the interface program must be guaranteed to run 24 hours a day. In this case, if we want to realize remote control on the network, we must firstly solve one of the most important problems, that is, how to realize the remote power-on, i.e., "network wake-up".

3 Remote control and remote wake-up realization

3.1 Realization of remote control

Install the control software pcAnywhere on the server and the user's computer respectively.

After running pcAnywhere on the server side, a certain port on the server side is in the listening state. In the server-side program can be specified to connect to the computer, other users or computer connection request will not be accepted. When the server-side program runs, the client runs the client program of the corresponding remote control program in the local computer, and specifies the server name or IP address to be connected when running this program, and the program searches for the specified computer name or IP address to all the networks after running. After searching, the client port sends out a TCP connection request, if the server port is listening to idle then respond and send a request confirmation signal to the client and at the same time sends out a confirmation box to the client to confirm the login user information, the login conditions such as illegitimate, then reject the user's connection.

3.2 Implementation of Remote Wake-up

There are two ways to implement the remote wake-up technique: Wake-upOnLAN (local area network power-on, or WOL for short) and Wake-UpOnModem (modem power-on, or WOM for short). We adopt the WOL method.

(1) To realize LAN power-on, both the motherboard and the network card must support Wake-on-LAN function. Motherboards that support Wake-on-LAN usually have a dedicated 3-prong socket to supply power to the NIC during shutdown. NICs that support Wake-on-LAN have a 3-pin WOL connector and a 3-prong Wake-on-LAN cable (some newer NICs may be able to support Wake-on-LAN without a WOL connector. This is because popular motherboards nowadays support the PCI2.2 standard, which does not require a dedicated WOL connector to supply power to the NIC, allowing the motherboard to provide Standby power to the NIC directly through the PCI slot).

(2) Insert one end of the Wake-on-LAN cable into the WOL connector of the NIC after the card is installed, and connect the other end to the 3-pin WOL Wake-on-LAN connector of the motherboard.

(3) CMOS setting: Set the "WakeUpOnLAN" item of "PowerManagementSetup" in CMOS setting to "Enable". Enable" in "PowerManagementSetup".

(4) The remote computer's network card will only receive special signals to activate the system boot, we also need to use the corresponding "Wake on LAN" software to generate these data frames.

4 Remote control and remote wake-up technology applications

Weighing control system and metering feeding system, the application of remote control and remote wake-up technology for our computer management provides a convenient service.

(1) Remote switching machine: it saves time and makes the work progress timely and efficiently.

(2) Remote technical support: through remote control technology, technicians can remotely control the user's computer, just like direct operation of the local computer, only need the user's simple help to get the machine there are problems with the first-hand materials, and soon find out where the problem is and solve it.

(3) Remote communication: the use of remote technology, so that technicians can realize and the user's remote communication, the use of interactive mode, through the actual operation to guide the user.

(4) Remote maintenance and management: network administrators or ordinary users can install and configure software, download and install software patches, configure applications and make system software settings for remote computers through remote control technology. Troubleshooting and error correction can be done in a timely manner.

(5) Remote file sharing and transfer: pcAnywhere provides synchronized folder transfer of files, but also through automated tasks, allowing the software to connect to a remote computer at a specified time for a specified file transfer operation in accordance with the user's settings.

5 Security of remote control

The security of remote control software requires great attention. In order to ensure network security, remote control software should provide remote connection authentication function, but also need to provide the function of dialog data encryption. For this reason, we chose the best security performance of pcAnywhere, which is powerful and supports almost all network connection methods and network protocols. In addition, while realizing remote control, pcAnywhere has a more complete security policy and password authentication mechanism to ensure the security of the remote controlled host. At the same time, it also has a dialog encryption function.