Hi,

Changes can be downloaded to the server without stoppping the OS visualization. An entire OS download will stop the OS visualization (and logging). The CPU continues to run it's program.

For this it is recommended to have redundant OS servers for a PCS7 project. Mainly because the process plants are large and have to maintain OS visualization at all times. 

In a redundant system, you can entire download one server while the other remains in runtime. After downloading, the server is put back into operation and normally you would wait until the synchronization is finished (synchronizing of alarms, tags etc.). Then the second server is downloaded and put back into operation and you are done.

Be carefull, because if you have made too many changes to the CFC logic, it could be that the system demands an entire download because too many tags have been changed. With a single OS server, it can be problematic because the server has to be stopped.

Hello,

When downloading to theOS (Operator Station)inPCS7, you have two main options:"Change" modeand"Entire" mode. These modes determine how much of the configuration will be transferred to the OS server and how it affects the running system.

Change Mode (Partial Download):

• Change mode allows you to download only the changes made to the project since the last download. This is typically a safer option for live systems, as it minimizes the impact on the running process.
• When to use:

Use Change mode when you've made minor updates, such as changing graphics, alarms, or tags.

This mode will not interrupt the processor stop the OS server from running, as it only updates the modified parts of the configuration.

It's ideal for situations where you need to make online modifications without impacting ongoing operations.

Entire Mode (Full Download):

• Entire mode downloads the complete OS configuration, replacing everything currently on the OS server with the new configuration.
• When to use:

Use Entire mode when there are major changes, such as adding new structures, objects, or significant configuration modifications that require a full download.

Be cautious becauseEntire mode can cause a process interruption.

Depending on your system configuration and how the OS is used, downloading inEntire modecan result in stopping the OS visualization and control for a short period, meaning operators could temporarily lose control of the process.

Will Entire Mode Stop the Process?

• Entire modewill likely cause a temporary interruption of theWinCC OS runtime, meaning that the operator interface could stop responding or display incorrect data during the download. The PLCs themselves will continue to control the process, butoperators may lose visibility and controlover the system temporarily while the download is in progress.

In critical systems, where the operator needs continuous control and monitoring, it is advised to avoidEntire modeunless you are certain that the changes will not affect critical operations.

Best Practice:

For live systems: UseChange modewhenever possible to minimize downtime and reduce the risk of impacting ongoing operations.

For significant changes: If you must useEntire mode, plan for amaintenance windowwhere it's safe to temporarily stop the OS server. Make sure all critical processes can run autonomously without operator intervention during the download.

Recommendation for Your Situation:

Since you're downloading to the OS (WinCC)and not the PLC, and if the changes are minor (such as updating a few screens or alarms), use the Change mode to avoid interrupting the operator's control of the system.

If you must perform a full download in Entire mode, ensure you do this during a time when it's acceptable for the OS server to be temporarily unavailable, as it may impact operator visibility and control.