Support for trace markers on a trend is currently in development for an upcoming release of PI Vision.
When you choose to see the markers that is because you need to see all the information stored in the system: is a graphical manner to see all the records, rather than going through a table. The graphical view of all samples enables to identify gaps, areas with high local variations etc.
Based on above when selecting to see markers, all of the data samples represented should have a marker, rather than an arbitrary part of them
I like the idea of switching to a line when there are too many markers over the trend duration.
But when markers are shown no one must be missing. Otherwise this would lead to misinterpretations of the trend.
We would need a marker for each value present in the Archive. Ideally, overring a marker could display a tooltip with date, value and questionnable status at least
Walter Huang commented
The requirement is for all data points to be shown.
Would be great if we could see every point with the capability to hover the cursor over each of them to see the value and timestamp (or other stats). The scooter bar in Vision is a poor substitute for the capabilities, in this regard, that are available in Processbook.
Matt Voll commented
"Would it be acceptable to show markers for only some of the raw values as long as there are enough to accurately represent the data, ...."
Absolutely NOT! This would make 'trace markers' uselss!
show all data points. I would expect, like Processbook, that if there were too many data points on the trend to be displayed properly that the markers would essentially turn off and the trace would merely be a line, until such time as the time range was shrunk to a point where ALL data points could be shown.
We would want ALL raw data points, just like ProcessBook.
In cases where we do want to use the "show markers" feature we will want to see ALL of the raw data points. This would be helpful for our tags where data is not written as frequent.I think it would be reason able to show ALL markers up to a certain number whatever that may be.
I know in Process Book when you have markers enabled it won't necessarily show any of the markers until you zoom in a bit if it's a busy pi tag while the less noisy tags show their respective markers without having to zoom in.
In response to Ryan McErlean, "We are currently researching this item a..."
We've had many requests from users for this feature. When you have a trend of data from samples that tend to have repetitive values, it's not easy to tell if a sample was forgotten or did not successfully write to PI. It looks the same from the trend. This would also help provide intuitive understanding of the frequency of the samples if you're not intimately aware of the sample routine.
Allow trend traces to appear as scatter instead of line. The normal trend symbol seems to perform far faster than XY plot. However, the trend symbol can only appear as a line and this reduces clarity for some use cases.
Clint Ostby commented
Once a trend marker has been set, users should have the ability to change the "start time" for other symbols on the display to match that trend marker's timestamp.
Ex. User has set a trend marker at 13:00, and would like an easy method to set all other symbols on the display to show values for that marker's timestamp.
It would be also great to avoid connection line between points as further option in 'format trend' to show plotted points. In genereal I think about discrete data values from measurements, etc.
Ramit Singh commented
Customer wants the option to disable the trace (i.e., connection between points) for specific trends to better represent the data.
The data in question is manually entered.
Will this also be an option on the Event Comparison trends? The ability to show only markers and really any format trend options would be nice to have.
Nate Anderson commented
The additional capability to show annotations and data quality information by dynamically changing the trace marker and then displaying the annotation data quality by cursor hover would be helpful
add markers, set trend line to "none". Important for general trends. Critical (for our users) in Event Trends. often, samples aren't taken until several hours into a batch. Trendline always ON makes it "connect-the-dots" from previous batch to first sample in new batch. Makes Event Trends unusable for us.
This would be a nice feature to have and also the ability to hide the line and just show the data points would be very beneficial to us.
Include actual data markers (plot each value stored in database) in the trend in PI Coresight(as in PI Processbook) so that we get to know at which point was value stored