Section 13.3
Troubleshooting Tags. Now,
this is a troubleshooting step that is reserved
for those times when you're just created some tags and, for
whatever reason, the tags are not getting data.
Heck we saw a lot of that when we were doing our exercises earlier. We kept creating
tags and no results, and it was usually a privilege
problem. So, first of all,
the tags, they are created, modified, etc. with
the System Manager Tool and
the PI SMT. But you can also use piconfig, the
Tag Configurator,
PI Point Builder plug-in. So, all those are ways of
editing tags. The changes, of course, they
are stored on the PI Server. So, again,
stating it one more time, even though we may do these edits
from a variety of locations, all the PI
tags are stored on the PI Point Database. I want to make this,
you know, real plain, because,
well, you know some of our, some of our
information -- so , for example, the,
some of the things we've presented already this week,
in which we describe interface
tags, tags associated with an interface. Sometimes
people get the impression that these tags are somehow stored on the interface.
That is absolutely not true. Remember,
we don't store the tags here. We don't really store anything
there unless there's a buffering situation. Now,
all of that, all the tag configurations are stored on the
PI Server. Just want to make sure that there's no ambiguity about
that. It's a very important principal. You know, we don't
store the tags on the Interface Nodes. They're all
stored on the PI Server.
Now, as we mentioned several times, the Update Manager
is going to queue up
those changes, if
there are changes, and then the interfaces will process
those, and then we will process them at the rate of 25
at a time, once every 30 seconds.
Now, if you do have a situation
which you need to, you need to troubleshoot,
here's a good set of steps to start with. First
of all, if the tag simply has the status
of Point Created, even if it's been two or
three minutes after it's been created, you really ought to check the
point configuration. What's probably happened
is you probably
have either gotten the location code 1 or the PointSource
wrong, See, it's in the PointSource and the location1
that we actually make the connection between the
interface and the tag. So, the first step
is if there's not data showing up, look
in pipc.log and see
if the interface picked up that tag.
You actually see that it says, you know, tag x
is added to the interface. Now,
if that's true, the, the log should indicate
if it was loaded with or without error. If it
simply says it's been added to the interface and there's nothing else,
then it should be getting data.
If not, you'll see what the error is. But,
if you don't see any mention of the tag
in pipc.log, then check PointSource
and location1. It's very likely
that you somehow did not make those agree
with the configuration on the interface. So, in fact, the
interface does not know that it's supposed to start scanning that
tag. Now, we've got a
helpful little utility for troubleshooting tags, and that
is this Stale and Bad Points plug-in.
Let me demonstrate. If we go into
Points -- whoops --
Stale
and Bad Points -- this is where when, when we
execute this, it's gonna go out and look for
any points that are, that are
simply stale. And by stale, we mean that we're not getting any data.
So this is gonna show
anything between this
four hours, anything between four hours
and 365 days where the data is stale.
Now,
by four hours and 365 days, what we mean here
is this has to be stale for at least
four hours. That's the minimum. So if
any of these values have been stale for four hours, they will show
up here, indicating that there's something wrong with them.
And then the maximum of, of one year --
the reason we have that is because sometimes there's a tag that you just, well,
you've kind of given up on it. It has been
stale for longer than a year, so you'd just like to ignore
that. So, anything longer than a, a year
of stale data, we're just gonna ignore it. So, for example, if I
can change, as we do in our directed exercise on the next page,
we can change this to, for example,
30 minutes -- and let's see, how many stale values
did we get? We got a fair amount of
stale values here that --
if I go ahead and set this to 30 minutes
and then search again, this is now
gonna find just those tags that -- or
all of those tags that have -- at least had stale
data for 30 minutes, which -- that's kind of short.
So, there are some legitimate tags that may have no data for
30 minutes. So, it's a nice little utility for
helping you find tags that are in trouble.
Now, if you come in one day
and you find that there's simply a flat line in
ProcessBook, it could be an indication, first of all,
that the interface has stopped abnormally. Now, by abnormally,
what I mean is it stopped
in some kind of a way in which it did not
have the time to write the status of
interface shutdown when it shutdown, so it perhaps had
crashed without being able to write that
during a regular shutdown. Or, of course, it could be
simply that you forgot to configure that. The \\stopstat,
that is making reference to this right here.
Internally that's used with the \\stopstat
switch, as you can see in the balloon help there.
You
can also see this kind of a problem if you've got some kind of a network
communication problem between the server
and, as a result, the interface has problems.
Now, that will immediately show
up in the I-O Rates which will fall to zero, and you can also
help detect that using Ping. So you can ping the interface
and see if the network is not available. Well,
we suggest, over and above all this,
is to use the Interface Status utility.
Now, if you've configured interfaces before,
the Interface Status utility is really very simple to
configure. In fact, I mean, we call it a utility,
but it's kind of like an interface itself. It's, it
runs and acts like an interface, and it simply watches
the activity of what we're calling a heartbeat tag.
And if that heartbeat tag from a PI interface
stops updating, then we send, we,
we change the value of a, of the tag for, for the Interface
Status utility, and we say that this,
this is no longer collecting data. So, it's a,
it's a nice little utility you can use. We don't really teach it in the
System Manager I class. We do teach that in our System
Manager II class.
But, again, it is
available to everybody who uses PI
and it's available for download from our tech support website.