Quickly set up workstations, distribute applications, and add redundant servers in the Hongke VTscada data acquisition and monitoring system

One of the most powerful features of VTscada is its ability to run on multiple servers. Configuration and historical data are synchronized between servers. When the primary server goes offline, the backup server will take over immediately, ensuring that your application will not be down due to a failure.

In larger applications, you can configure separate server lists for various services in VTScada (such as alarm manager and data logger) to distribute the load.

Multi-server applications can also have client workstations-just a simple vtscada workstation, not configured as a server. Operators can operate at these sites, and developers can build projects. But the client workstation cannot take over work when the server goes down.

Use small tips

• port

VTScada uses IANA to register port 5780

• version

All computers must run the same version of VTScada

• Usage requirements
  (1) VTScada license for each computer, among which those computers to be used as servers must have server functions and redundant function licenses.
  (2) All workstations are connected to the intranet.

Master server configuration process

Ready to work

• Install VTScada on two or more computers, and its license should include allowing server operation
• Ensure that computers can communicate across the network
• Create an application to run on multiple servers
• Enable security and create one or more accounts. After security is enabled, only users with "configuration" or "administrative" permissions can pull applications to other workstations
• Run the application on a single workstation. Do not copy the application directly to other workstations

Add the main server

On the workstation with the application:

• In the application, open the VTScada application settings
• Select Edit Server Lists
  
• Your workstation should be listed as an available server. If not, type the name of the workstation as an available server. Click the "+" button
  
• Click the "apply" button in the lower right corner of the dialog box and save your settings

Get the app from the workstation

During the process of setting up multiple servers, applications must be installed on these computers. The option to obtain from the server is preferred to facilitate the distribution of the application among the computers connected on the network.

By using this method, you can ensure that the latest version of the application is installed and that future updates are automatically distributed (assuming the server list is configured correctly). If the application is based on the OEM layer and the OEM layer exists on the server, the OEM configuration will also be obtained when the application is obtained.

On a workstation outside the server

• Go to another workstation where VTScada is installed
• Open the Add Application Wizard from VAM
• Select the "advance" option in the first panel and click "next"
• Select the "Get From Workstation" option in the second panel, and then click "next"
• Select (or type) the name of the workstation where the application is currently running, and enter the machine name or IP
  address of the workstation that contains the application . On a network with a properly configured domain name server, all local computers with VTScada installed can be selected in the drop-down list, and then click "next"
  
• Select an application from the list of available applications, * indicates the existing application on the workstation, and then click "next". You will be prompted to enter your username and password. You must have configuration rights.
  
• Click finish
• Repeat the above steps for other workstations
• Adding applications in this way can easily use the local computer as the workstation of the main server and synchronize operations. The specific form of implementation is that all I/O communications are handled by the main server. The control operations of other workstations are first transferred to the main server and then to the device. Data logging is done on the primary server and then copied to the backup server
• The picture shows the remote access screen of the local workstation and the main server. The verification shows that the operation of the workstation is synchronized with the remote end. The
  
  following describes how to add a backup server with one click.
  There are many options and variables to choose from for vtscada server service and load task distribution, which will be described in a later article.

Add a backup server

On any workstation

• On any workstation, open the "Application Configuration" to the "Edit Server Lists" tab.
• Add the name of the backup server to the list
• The workstation name at the top of the public server list is the main server, followed by the backup server in the order of the list.
  
  At this point, the backup server is added with one click. No more configuration and operations are required. Vtscada will automatically complete the data synchronization in the background.

verification

Use TraceViewer to view the running status of the application service on each server, and measure the running status of the backup server when the main server is down to verify that the server has completed the backup.

• Open TraceViewer on the backup server, the function we use here is to monitor the applications running in the backup server at the moment

• Choose to monitor remote procedure call diagnosis, you can monitor all servers and machine-to-machine communication between workstations.
  
• Then select RPC Diagnostics -Services in the navigation bar to view the service operation
  
• The service operation is as follows:
  
• Stop the main server application, you can observe that all application running related services are taken over by the backup server when the main server shuts down
  
• The main server is disconnected and reconnected. Restart the application on the main server, the main server will gradually take over the service again as the application starts. Because it is necessary to synchronize data records and changes during shutdown at the same time as the application is started
  

Precautions

DNS

VTscada assumes that you have correctly configured DNS. This does not necessarily apply to all situations. If the local network does not have DNS, you need to set the RPCConnectStrategy property of Setup.INI to a valid value.

Workstation name

VTScada relies on Windows® operating system function calls to obtain the NetBios name of the workstation. This function will truncate the name of more than 15 characters, so it is recommended to limit the workstation name to 15 characters or less.

The impact of NAT on VTSCADA

Network address translation (NAT) routers have compatibility issues with Vtscada, and you need to know your network topology.

Each thick client server must have a unique IP address. The NAT device will cause the same IP address to be assigned to multiple servers. VTScada cannot run in this environment.

As shown in the figure below, the NAT device will cause both server B and server C to appear in server A as if they were on the same IP address.

in conclusion

This article mainly explains how to configure the client server of the VTscada data collection and monitoring system, as well as the addition of redundant backup servers/client workstations based on Vtscada, the rapid configuration of workstation application distribution, and the verification of its effect shows the flexibility of its development. It can greatly accelerate the progress of the project landing, and achieve the effect of plug-and-play and fast maintenance.