Scenario:

• Redundant server configuration (Primary + Backup)
• Primary server online and working OK
• Backup server ready but in standby mode (no coms/history..)
• Several Operator Workstation on local network
• The operators normally logged in Primary server

Then, primary server shuts down by any anomaly or forced event.

The question is how the Operator Workstations recover connection with Backup server. Is that authomatic or the the operator should perform a new logon in Secondary server?

If the backup server is running and is in the Internet Client server list (not the application server list - two different settings), then fail over should be automatic for anyone on the same network.

If the connection is external - from a home PC using a web browser for example - then it may require changing the URL to go to the backup server and a new sign in. That part depends entirely on how the router handles the port forwarding.

To add to this, any currently connected user, at the time of the failover, should automatically be forwarded to the backup server so long as the server list contains a valid URL for the client to connect to the backup server.

Thank very much for your explanation.

As we are evaluating VTScada, can we test redundancy workstation failover with your 90 day free license?
Where I can find the proper configuration dialogs in VTScada?

The easy way to get started on that is by reading the procedure in our help files, found here: https://www.trihedral.com/help/Content/D_Internet/Dev_GeneralVTSIS_steps.htm

Also, you can also find more detailed instruction for this in the Client / Server Configuration instruction in our developer's guidebook, found here: https://www.trihedral.com/wp-content/uploads/2016/09/VTScada11-2-DevelopersGuide.pdf

Note that while VTScadaLight installations can be redundant servers to other VTScadaLight installations. You can only add the local machine to the internet server list. Also, not that this also prevents access to these thin clients over the internet. You must be able to connect via the workstation name, IE: on a LAN/WAN/VPN.

If using the 90-day trial, you should be able to test the full features of the product.

NOTE: While there is no limit on the number of servers you can add to an application; you can only connect VTScadaLight's to VTScadaLight's, 90-Day Trials to 90-Day Trials, and Full licenses to Full licenses.

Doug just called me to remind me that VTScadaLight has some thin client restrictions, not part of the full product. Please note that have updated my response above.