Graph Wizard features a 'display mode' button within each graph... its one of the buttons in the small tool bar that hangs onto the right edge of every graph box!
It’s worth considering how data is gathered, stored and then used to understand the benefit of Display mode...
- As you will likely know, SCADAR data loggers are pre-configured to sample data once every second. If an audit lasted for exactly 1 week, that’s 604,800 samples of data!
- SCADAR.NET (the browser based software) offers a display resolution support down to 1024 x 768 pixel which is common place. So that’s a maximum horizontal display resolution of just 1024 pixels 'on screen'. And that’s before we put the browser (e.g. Chrome) on the display or SCADAR.NET onto the chosen browser.
For graphs themselves, SCADAR.NET actually plots 250 pixels across a horizontal graph axis! So if you were to load a graph with a time span of 1 week, we need to somehow plot 604,800 samples onto 250 pixels which is of course impossible… If you think about it, the only time SCADAR.NET can ‘truly’ plot samples directly from its database onto a graph is when the time span is equal to 4 minutes and 10 seconds or 250 samples (250 samples = 250 pixels!). And if you ever wondered why you can’t zoom to a resolution greater than what looks like 4 or 5 minutes on the graph horizontal axis, well now you know! This understood, its worth remembering as you zoom into any graph that the effects of ‘Display mode’ diminish until they have no effect when you have zoomed into 4 minutes and 10 seconds of data.
To help with this ‘display challenge’, SCADAR.NET offers 3 Display modes; ‘Actual data’ (default), ‘Average data’ and ‘Peak data’. Each mode has an alternative method to display more data than the available pixel real estate.
Actual data looks at the number of available samples (e.g. 604,800 over 1 week), SCADAR.NET then divides the data into 250 equal sizes groups of data and takes the first sample in each of those equally sized groups to plot a graph. The benefit of this Display method is that you are displaying real data. However the display method has limited benefit at lower resolution because large amounts of data are simply omitted from the graph.
Peak data again looks at the number of available samples (e.g. 604,800 over 1 week), And again, SCADAR.NET divides the data into 250 equal sizes groups of data but this time, SCADAR.NET takes the single largest sample within each group to plot a graph. The benefit if this Display method is that a User can easily find data peaks and peak trends in data which can be if particular interest.
Average data again looks at the number of available samples (e.g. 604,800 over 1 week), And again, SCADAR.NET divides the data into 250 equal sizes groups of data but this time SCADAR.NET takes the number of samples within each group and establishes an average value for each group (e.g. 604,800 / 250 = 2,419 samples / by the sum of the sample data within each group). The benefit if this Display method is that all available samples have contributed to producing the graph. However some caution should be exercised when analyzing average data and its beneficial to assess its value alongside the either Peak or Actual data or both.
There is no definitive answer to which Display method is best, it often depends in what data is being graphed and the specific area of focus.