Sample time in trend
i am working with ABB Industrial IT 800xA trends. I need to get certain data from history for a period of a month, but the sample time should not be bigger then 20 seconds.
Unless i configure the time i will always get samples in few hours, or i have to do a lot of manual labor to achieve what i want... There must be an easier way.
Has anyone set trends to sample this way? How is it done?
Thank you in advance,
Voted best answer
First you must use Log template to define the data collection parameters.
Set the MinTime to 20 seconds or lesser and Set MaxTime to greater than 2*MinTime.
And Storage Time to 30 days in log template aspect.
Then create the log configuration aspect on the object for the data logging.
Refer 800xA SV 5.1 Configuration Manual for more details on how to log data in 800xA System. (Ref 3BDS011222-510_A_en_System_800xA_5.1_Configuration)
You can configure the data collection as Arihant already described. The history logs can easily store 20 second data for several months.
However, you cannot display this data on a trend aspect for a full month - there is simply too much data. The Trend Aspect will always compress your data before displaying it. To make the problem even worse, when you zoom in from a 1 month trend, the data stays compressed, so you will never get the high resolution data you are asking for.
The only way to work around this problem and display all of the data samples is to keep the 800xA trend display zoomed in to a period of a few hours and either scroll or type in the start and end times.
Unfortunately there does not seem to be any way of displaying long time periods of data with this precision using the standard 800xA displays ( other than the work around I described aboive). Every solution I have seen involves using a third party historian ( OSI PI )