Alarm names and Dispay paths

I’m having a play with Version 7.6 beta6 and I have a question about the new alarm configuration page.

In a data type, I’d like to put a couple of string tags that are within the data type as part of the name or Display Path but I can’t seem to get the syntax right

For the display path I can only seem to select one tag, what I’d like is something like the following
“Site_Name” [.]PDU_Name/" "/[.]MCB_Name
With an output of
“Site1 PDU1 MCB1”
I read that the “/” is a separator but unsure how it works



The fact that display path is a “path” doesn’t mean a lot right now, but will become more useful when we make components like trees that let you browse down by source or display path. It’s perfectly fine if your display path doesn’t include “/”, it would then technically be a path of only 1 element.

Anyhow, in certainly [del]is[/del] will be possible to do what you want. (big note: Unfortunately as I tried to mock this up in order to verify everything, I found a few problems that would keep this from working in the current beta. They’ve been fixed for the release. So, I’ll describe the procedure, but you’ll have to wait to try it)

Fundamentally, you’re going to bind the display path to an “expression”. The job of this expression is to return a string. For your example (which isn’t 100% clear to me, but I assume is using 3 tags), the easiest way is:

concat({[.]Site_Name}, " ", {[.]PDU_Name}, " ", {[.]MCB_Name})

Now, it seems to me that these parameters aren’t really ever going to change (though I could be wrong). If so, the performance would be better to use UDT Parameters instead. If using only UDT parameters, you don’t need to bind the display path value, you can just type them in directly:

Display path: {Site_Name} {PDU_Name} {MCB_Name}

Note: I’ve used the same names, but remember, these would be defined as parameters on the data type.

If you want to mix udt parameters and tag references, you can do that, but remember that UDT parameters get expanded before the expression is parsed. So if your site name was a tag, but the other two were parameters, the correct syntax would be:

concat({[.]Site_Name}, " {PDU_Name} {MCB_Name}")

So, you see, the references are inside the quotes, because they’ll get replace with the actual values before the expression is parsed. If they were outside the quotes, they would look like non-existent keywords to the system.

Sorry for the inconvenience of not being able to try this out, but at least I can say that it’ll work for the next update/actual release.


Thanks Colby

The reason for using tags within the UDT is that, for my systems, the MCB names and PDU names may not be known until well into the project and can change after that, it will allow the customer to change them on the fly and still have the correct name as part of the alarm.

I’m quietly pleased you couldn’t get it to work, I tried a lot of different expressions, I’ll wait for the release, but it’s great that it’s going to be included, it will reduce my development time for some projects.