Trends in factorytalk view

Hi guys,
I am trying to get my head around using trends in FTV. As per the manual a data-log model is required to view historical data, but tried creating a trend with a system value(ex- minute ) and I could view data from the past time as well as the real time.

Hence what exactly is the role of data log models??

I am little confused with this ....Pls help

http://www.plctalk.net/qanda/showthread.php?t=113570

http://www.plctalk.net/qanda/showthread.php?t=47950

http://www.plctalk.net/qanda/showthread.php?t=85989

The above links may help you out.
Regards,

rejoe.koshy said:

Hi guys,
I am trying to get my head around using trends in FTV. As per the manual a data-log model is required to view historical data, but tried creating a trend with a system value(ex- minute ) and I could view data from the past time as well as the real time.

Hence what exactly is the role of data log models??

I am little confused with this ....Pls help

Click to expand...

I mean I am able to view historical values in my trend with a data log model so why do I need data log models in the first place.

Create a trend on a window without a datalog. You should see data. Now navigate to a different window and then come back to the trend window. There is your answer.

Phrog30 said:

Create a trend on a window without a datalog. You should see data. Now navigate to a different window and then come back to the trend window. There is your answer.

Click to expand...

Ok so, is the poll time of the trend basically the log trigger time of the date model??

It can match the data log periodic interval, but it doesn't have to.

For example, lets say your datalog is logging once per minute. Then you setup the trend with a 1 second update. While the trend window is open, the trend will update every second with "live" data and once per minute with historical data from the log.

If you navigate away from that window (close it) and then return, you will not see that "live" data, only the logged data will display and it will start over with new "live" data.

There is a setting on the trend (General tab I think) where you can select "real-time" or "historical only". If you select historical only, then you would only get the data from the log. If you select real-time, you get both.

OG

Oh!..wonderfully explained ..Thank you !!