What is the capacity of historicizing of 2016 Freelance?
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There are 4 main differences between the native Freelance Archives and the Decathlon Services for History.
1. Freelance doesn't do data reduction for floating point signals. That means, if the signal changes slightly only (and floating point value do that even if they seem to be constant), Freelance will still store the data with each sample. Usually specialized archive packages do data reduction according to a boxing algorithm, that stores new data only if changes exceed a certain threshold. That means that usually Freelance archives need more disk space than the same archive in Decathlon Services.
With todays hard disk prices that usually is no decision making difference with regards to price. Performance is another issue. If you need to store slow changing floating point signals sampled with one second for a year or longer then the archive files could differ significantly in size. To open a 1 GB history file and browse to the past can take some seconds, even in Freelance.
2. If you want to see the same history on several operator stations you would need to configure the same archive on those operator stations, because Freelance Operation only shows history data that itself has sampled and stored on the local disk. This is also an easy way for archive redundancy, but there is no back-fill if one FO was offline for some time.
This implementation also leads to archives looking slightly different on different operator stations, if the frequency of your process signal is bigger than approx 5 times your sample frequency. Imagine a signal with a sine wave with a freqency of 1 Hertz. if your sample time was 2 Hertz you would do 2 samples within one sine wave period. Because different operator stations sample at different times, the results will look different. The curves would look identical if your sample frequency is at least 10 times of your signal frequency.
To be frank, if you sample a process signal slower than that you make something basically wrong idenpendant of the archiving package you choose.
So if you don't need back-fill, Freelance native archiving function is sufficient.
3. If you need to sample data from different Freelance systems in one archive then Decathlon has an advantage. Freelance native archives only store data from that same project you configured the archive in. If you have 2 projects (proj_1 and proj_2) then an archive you configured in proj_1 doesn't know about variables in proj_2 and therefore cannot archive them.
There is a way around that limitation by using send & receive function blocks or the PLC integration function to shuffle data between the projects, but it needs extra configuration effort and the number of signals is limited.
Freelance native archiving is included in the basic Freelance Software.
Freelance native archives are a good solution if you need essential archiving functions, even redundant archives and only need to see few data from outside your project.
If you need redundancy with back-fill, or want to collect data from more than one Freelance project or you have a lot of slow changing floating point signals you need to collect "forever" go for Decathlon services.
Interesting question...., to keep it simple one can eat as much stomach allows and there are some other factor then stomach size. So one can archive as much hard disk size allows.
Note that Trend and logs can be archived locally on Freelance operator station or via FTP at some central location.
In Freelance 2016 and older versions, While configuring Trend as per IEC 61311-3 format user can set duration for archiving data upto 24855d equal to 68 years.
The size of trend file is determined by the archiving duration. A good design that while user is configuring trend archiving duration history data storage size automatically get calculated by system for that particular trend acquisition block.
The archiving file size never be exceeded by trend file since data are stored in a ring memory, that means older data overwritten by new current data when archiving file size rached....
And there is Archive browser previously known as digibrowse, user can use this tool on any PC and can browse history offline. It's independent tool user don't need Freelance installed or don't have any dependency in browsing archive/history...Check more details in manual 3BDD012518 Engineering - Operator Station Configuration.pdf
So based on your need you can go for local/central history storage OR can check for Decathlon software for historian as external option then Symphony Plus
For that Check more details @ http://new.abb.com/cpm/decathlon-software/data-collection
Hope that gives you some idea...