Linked excel objects in a powerpoint show

I had a question if its possible to get an answer. I was wondering how to keep the information updating automatically in my powerpoint show. I know how to set the link excel objects to "automatic" via the Edit>Link> Automatic route..

I have been messing around and it seems like the excell file has to be open if i am using an excel object linked in powerpoint, and that the feed will not automatically update while the slideshow is actually being presented. Is this right or am I doing something wrong?

It seems to only update when the slideshow is in its editing mode or now being viewed.. Ideally I want to have powerpoint pulling a stock feed from the excell file on the server that constantly updates in real time the slides and objects that are being displayed (looped, continuously) while playing in the companies lobby. And everytime that excel file gets changed i want it to update the Show, Via the linked objects, Without having to stop the show, close reopen and tell it to "update all objects".

Any suggestions? Thanks

Warmest Regards,
Ben