Use Automator for saving file on NAS, what happen if NAS is not accessible? I'm still new with OS X and have learned how to use Automator for zipping a folder in one file, named with date, on my Hard Disk. I saved the set of actions as an app. I'm planning to use Calendar to run it daily at 1pm. This should work fine.

I'm using the French language for Automator (trying to translate the called Actions) :
1. Get elements/items in Finder (I fill in the folder I want to backup)
2. Create an archive (I fill in the target and the name I want for the archive) – screenshot

If I want to save the zip archive on my NAS, (ReadyNAS 312) rather than on my Hard Disk, what will happen at 1PM when the NAS is not working (powered off, no network connectivity, etc.)?

In my tiny Automator script, do I have to "test" if the NAS is connected before running the archiving action? If so, what is the right (and easy) way with Automator?
It's normally a good idea to check for the existence of an external disk before using it. In this case, however, automator won't display an error if the disk is not found, it just won't do anything. I'd say it's safe in this instance.