Hi,

It really depends which changes you need to download. In most cases, an OS download change is sufficiënt. But sometimes the amount of changes are so big, they cannot be downloaded with a change. This is checked upfront before download of the server(s). 

Some changes need a full OS download. In a non-redundant system, it means the operator looses visualization. In redundant OS server system, you are able to download each server fully one after another so the operator won't loose visualization.

Changes that need a full download:

• OS was renamed
• A OS entire compile was executed
• The path to the OS computer was changed
• The assignment master/standby was changed
• and some more which are described in the manual: Engineering System chapter 9.2

Take a look at the PCS 7 Compendium Part A chapter 11. There is described what it means to download changes or a full download.

Hi VeeKy,

Oh I'm sorry, I misread your post.

OS client is only to be downloaded if you made changes in the OS client project like for example: 

• Updating OS project editor
• Changes to User Administration
• Added/Deleted/Changed scripts C or VBS
• Added a server package from another OS server
• etc...

A normal procedure looks like this:

1. Change CFC logic in AS project and download changes
2. Execute OS compile (considering changes to OS are executed in step 1, for example adding an interlock block)
3. Download change OS server(s)

You won't need to download the OS client in this case.