HMI Tag Analyzer

HMI Tag Analyzer is a Windows app for analyzing SEL Diagram Builder .hprb HMI files for errors, namely invalid tag references and reused tags.

This project has no affiliation with SEL. SEL Diagram Builder is closed source, but some kind SEL engineer included an API, which you will find in c:\Program Files\SEL\AcSELerator\DiagramBuilder\bin\api\SEL.API.dll, that I used for this project.

Background

HMIs? Tags??

In electrical substations, such as those my brother's company designs protection settings for, operators need to understand what's going on with the many circuit breakers, transformers, switches and busbars. So, on a computer somewhere, there runs the substation HMI ('human machine interface'). The HMI is schematic representation of the substation. The HMI shows the voltage and current at various points, visually depicts the state of circuit breakers and switches, and often has 'controls' that let an operator open or close circuit breakers.

Here is the bottom half of a HMI for a substation:

.

You will notice there is a lot of repetition - e.g. between HVSLJ21 and HVSLJ22, and also between J1 through to J6.

Here I have zoomed in on HVSLJ21's J06, and also clicked A phase voltage. On the right you'll see the source of this voltage - a labelled data point called a tag. This particular tag is atag.HVSL21_J06_A_Phase_Current:

There are, all up, 12 tags used in just J06:

atag.HVSL21_J06_A_Phase_Current
atag.HVSL21_J06_B_Phase_Current
atag.HVSL21_J06_C_Phase_Current
dtag.HVSL21_J06_Q1_DS_a
dtag.HVSL21_J06_Q1_DS_b
dtag.HVSL21_J06_Q1_ES_a
dtag.HVSL21_J06_Q1_ES_b
dtag.HVSL21_J06_Protection_Trip
dtag.HVSL21_J06_Q0_CB_Open_Control
dtag.HVSL21_J06_Q0_CB_Close_Control

A HMI will typically contain hundreds of tags. All very alike. All hidden in the settings of graphical widgets. All set one by one, by the HMI designer.

I hope you see the problem HMI designers face: it is very easy to muck up the tags. For instance:

• you forget to set a tag on a widget altogether
• you copy and paste (e.g. J05 to J06) and forget to alter all the tag names in your copy.
• your tags change (e.g. a tag is renamed upstream), and your widgets now refer to a non-existent tag.

There is no easy way (that I know of) to simulate tag values to let you see how your HMI responds. The only testing is physical, during deployment (which is taken very seriously), and if this doesn't catch a mistake there could be very real-world sparks-and-outages consequences.

What the HMI Tag Analyzer does

The HMI Tag Analyzer takes a .hprb file, as generated by SEL Diagram Builder, and looks through all the tags used, and generates a tag usage report:

Invalid tags

'Tags' are just named data points available to the HMI from its host computer, called an RTAC (real-time automation controller). The HMI designer must import the tag set from the RTAC, often multiple times as new settings and tags are created:

SEL Diagram Builder won't let you use a non-existent tag, if a tag changes its name or is deleted, your only indication is a yellow ⊖ on the widget:

In the HMI Tag Analyzer, the Invalid Tag References section shows all such invalid tag references.

Re-used tags

Consider J06 again:

Let's say J06 was copied from J05. The J06 A, B and C phase current tags are:

Do you see the mistake? C phase uses the J05 tag rather than J06!

This mistake can be caught be carefully reviewing the Re-used Tags section:

Many tags are legitimately used more than once -- for example, the Protection_Trip tags are used both in a label and an opaque overlay to prevent an underlying control being used during a protection trip. But atag.HVSL21_J05_C_Phase_Current should not be used more than once.

Used Tags

The Used Tags list may be useful for comparing with the source of your tags, such as a spreadsheet. If a tag is in your source spreadsheet, but not in Used Tags, then something is missing or wrong in the HMI.

Installation

You will need:

• HMITagAnalyzer.exe from the Releases page
• .NET Framework 4.6.2.
• SEL Diagram Builder - installed for the dll, c:\Program Files\SEL\AcSELerator\DiagramBuilder\bin\api\SEL.API.dll

Shortcomings

• Currently the app is cumulative, i.e. if you load a.hprb and then b.hprb, you will see tags for both files, and need to restart it to reset.
• This was my first C# project, written with autocomplete and ChatGPT. The code is terrible.