Alarm Permissions changes

New Permissions

As part of the ongoing work to improve access control in Centrix, new permissions have been added for alarm:

• Edit Alarm - permission to create new alarms, edit the configuration of existing alarms and delete alarms.
• Clear Alarm - permission to clear the status of an alarm (acknowledge it).
  
  

Alarm View Changes

The screenshots below shows the alarm detail page from the perspective of a user with the "Edit Alarm" permission (Site Admin role) and a user without the "Edit Alarm" (User role).

Only users with the "Site Admin" role can edit alarms detail, users with just the "User" role can see the alarm details but in a read-only view. The save and delete buttons have also been removed in the read-only view.

The create buttons on the alarm management page will also not appear for users without the "Site Admin" role.

Playback Loading Issues 

We have introduced some performance optimisations that should resolve issues when loading the playback page for certain sites. In some cases the page would "timeout" during the loading process which would result in an error similar to below:

Other sites would load successfully but take a long time to retrieve the list of alarm raises.

Triggers on Capture Trace Graphs

Start and end trigger are now displayed on the capture trace graph if the channel uses the trigger capture mechanism and the data logger is configured to push them to Centrix. 

There are now 4 options for aligning the traces and the start and end trigger times are shown (if applicable) on the panel below the graph.

By selecting one of the options in the sync traces dropdown, the traces will be shifted. 

By default, the start of the traces will be aligned:

 The figure on the right shows traces where the end trigger times have been aligned.

Zero stripping Capture Traces

Generally, loggers 'zero strip' capture data to remove 'zeroes' before and after the actual trace.

The values removed are the essentially the loggers background value from the analogue sensor, they therefore may not be exactly zero.

These values are not useful, they are noise and clutter the data.

If for any reason a logger doesn't remove these values from the trace, Centrix is now able to check the traces and remove them.

Below is an example of a trace without these values removed:

It can be seen that there is a flat line offset before and after the actual trace data.

Below shows the result of these values being removed:

Points Alarm Wizard Results

The points alarm wizard outputs alarm thresholds for swing duration, average trace value and peak trace value. 

These threshold values can now be manually tweaked if required. Although generally it is not advised to do so.

The standard deviation of the values from all the traces used by the wizard is also shown. 

This can be used as a sanity check that the inputted 'training' data is, at the very least, consistent with itself.

If the training data all has similar traces, then the standard deviation will be very low.

If for some reason (e.g. weather conditions) the training data contains of multiple clusters of similar data, this may be bad training data. 

If the standard deviation is large with respect to the actual threshold values, further investigation may be needed.

Points performance graph

The points performance graph is shown as its own report and on the alarm raise page.

A green region is drawn on the graph to show where the 'normal operating region' of the points machine is. 

For the report, this is based on all the data within the date range. For the alarm raise page, it is based on the last 90 days of data prior to the alarm raise. 

The idea being, you can easily identify whether more recent points (which can be highlighted as red squares) have been systematically drifting outside of this region.

The region is calculated using a statistical method called Kernel Density Estimation. 

In previous versions of Centrix, a 1 dimensional kernel density estimation was made in both the x and the y direction and the results of these two calculations were combined to draw an ellipse:

The current version of Centrix now uses a 2 dimensional kernel density estimation so that one calculation is made which incorporates both directions.

The result is a much more precise shape around the data points: 

The shape is also much more general. Statistically, the majority of the points data may lie within multiple distinct regions. 

By default, the region drawn encompasses where 95% of points data can be expected to fall. This fraction can be decreased (e.g. to 50%) to demonstrate multiple regions being drawn:

Multiple regions seen in real data implies the points machine has more than one typical operating region. It may therefore be subject to scrutiny.

Minor amendments and fixed issues

• Bug fix: sorting by site on reports page did not work
• Bug fix: The button to "inspect on graph" from an alarm raise did not work
• Bug fix: The button to view a channel on the inspect graph from the general search results list did not work
• Bug fix: When filtering a list to reduce its size, some types of "Select All" buttons weren't updating. This would result in selecting more items than intended.
• Bug fix: Y-axis scale updates correctly when adding and removing traces from the Inspect Captures graph
• Bug fix: Entering '0' into map latitude or longitude values did not work. 
• Bug fix: Clicking on map to set latitude and longitude for new assets did not work.