If the client - system connection or the server advise connection cannot be established, ViewX will show the system as being 'Offline'. Users will not be able to use the client to interact with your system.
The connections will fail to establish if:
- There is a network failure. You will have to investigate your network infrastructure and repair any faults.
- A firewall is in place and is incorrectly configured. The firewall has to allow the client to send data to the server’s incoming port (5481 by default).
An additional requirement applies if either end of the connection (server or client) is running a version of Geo SCADA Expert that is earlier than Geo SCADA Expert 2020. If so, the firewall also has to allow the server to send data via the server advise connection (which uses one of the ports in the client’s Sockets range, 5500 to 5509 inclusive by default). For more information, see Firewall Settings for Client - System and Server Advise Connections.
- The server is required to use certificates for server - client communications and either:
- The server does not have a valid certificate
- The server's certificate has expired and needs renewing
- The server is using a temporary self-signed certificate, but the client is configured only to accept connections to servers that have valid certificates that have been obtained from a trusted certificate authority (CA) (see Configure the Client Connection Security Settings)
- The client uses a client certificate for server - client connections and either:
- The client does not have a valid certificate
- The client's certificate has expired and needs renewing
- The client's certificate has been renewed but the Connection Security settings on the client machine specify a specific certificate and those settings have not been updated to reference the renewed certificate (see Configure the Client Connection Security Settings)
- IPv6 addressing is defined and is used in the client connections, but is not supported by the target host server or the intervening network.
If a server is unable to supply a 'floating license' to a ViewX client, the node cost of that server increases. This enables the ViewX client to switch to a server that can supply a floating license. For more information, see Define the Node Cost for a Client - System Connection.
Further Information
Firewall Settings for Client - System and Server Advise Connections.
Understanding Client - System and Server Advise Connections.
Certificates for Geo SCADA Expert Server and Client Connections.
Use the Server Status Tool to ascertain the current status of server - client connections: see Server Status Information.