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Here is something that we have seen a
couple of times already just in passing. We are in
System Management Tools and we want to look at the
Point Builder. So if I go into the Points section and choose Point Builder,
there is the graphical user interface for using
PI Tags. I would add, here is the interface
for building tags one at a time. If you have
10,000 tags to build, nobody
would build it using this tool as it would take too long.
But to create tags or edit existing tags, I
can use this to search for existing tags or just
choose new. And then just create a new
tag, so I will call this mytest1. And I would
assign it all the proper attributes based on my
needs. So for example, let's pretend
I am creating a laboratory tab. I will choose
Point Source of lab and let's
say this is going to be a float32. And for the engineering
units, we will say that this is measuring
parts per million.
And this is my test for class manual
input tag.
Now there are all types of attributes and we are
going to be looking at these attributes as we go through and study
the different tag attributes-- things like source tag for outputs etc.
But I will just stick with some of the basics here.
I have given it a name. I need to give it a
0 and a span and an engineering unit. The
default is a span of 100. So let's
say this is actually going from 0 to 40,000.
And the typical value is around 25,000.
And then depending on what
my needs are, I can set the compression settings
as I like. For example, with a
laboratory tag, I would probably set compression
equal to off. And for a lab tag also,
I probably would not even worry about the exception
deviation. It would not make any difference because there is no interface
involved here. It's simply something that is being added manually.
So I would go through and change
all the attributes that are necessary. Classic is
where we would go to change those settings required for specific
interfaces. That's a pretty bland statement. We
have not described this at all yet. Because basically you cannot
describe this until you start discussing a specific
interface. So in this class, we use the
OPC interface as an example. Later when we create
OPC tags, we will come back and take a look at them as an
example of what you would put in these fields for instrument tag, location codes etc.
So these are all the different
parameters... Security
settings.... These are the system parameters... It looks like you can edit these, but you cannot.
These are just read only fields.
Once I am good and set and this looks good, I will go ahead and save this.
And now that I have saved it, it becomes a
PI Tag that I can use in any application. So for example,
I can go out to ProcessBook and launch ProcessBook and add this.
Or I can go into, let's
say let's go look at the recorded values for this.
I will go out and look for all the tags that begin with the
letters MY.
And we find mytest1
and so let's see if we can get the events.
And here it is. It has been created so it has a single
value and that is the digital state point created.
So that's how I create a
tag, one tag at a time.