Hello John,
The yellow flash means the symbol received realtime price update.
If "Update on every tick" is enabled:
Pre-scanner calculates the scripts upon Rescan. There can be multiple new ticks, therefore multiple study calculations, while Rescan is being done.
Watchlist calculates the scripts upon each new incoming tick.
Thanks Henry. Maybe I misinterpreted your answer but it sounds like you are saying that the studies in the pre-scanner section do not get run until a ReScan of all symbols is executed. However my tests suggest otherwise. Here is what I have noticed.
First I unchecked the checkbox which initiates ReScans every X minutes. I also do not click the button that forces a ReScan. Lastly all the script entries in the Pre-Scanning section are checked as "Update on every tick". In this situation I have noticed that Pre-Scanning section shows the yellow flashes suggesting it is executing the studies. So I was wondering if it might be executing them but not as often as I want so I decided to write out a file append during last bar on chart. So when I did this I noticed that the file was growing very quickly suggesting that just maybe it is running the script on every tick. So this would make sense since each cell of the Pre-Scanning section is set with properties "Update on every tick". It does not surprise me that there is a bit of a delay/catch-up going on. That's fine.
Regarding the use of the watchlist I find the single criteria for loading it during Pre-Scanning is not adequate so I have used my database program to take care of that as I mentioned in another post. It all seems good so far. I have a lot of entries in the pre-scanning section. MC has complained about memory so I upgraded to 16 gig. It still complains so I am going to reduce the number of entries for now. Eventually when everything is finalized I will know how many (symbols X resolutions) I can process based upon the Global Variables limit. It may just be that this limit comes in below the Scanner's limitations such that I get no memory warnings from the Scanner even with 16 gig. I learned today that I can get computer's with a motherboard with 4 memory slots that can take 16 gig memory sticks for up to 64 gig of memory max (the store I called has not seen a computer that can handle the 96 gig capacity of Win 7).