Tag Query with Special Characters in Tag Name not working

[former_member189057]

Hello-

We are on SAP xMII 12.0 sp8.6, connecting to Honeywell's PHD. We are doing Tag Queries, and all is working well, except when there are special characters in the Tag Name (+, /, \) We have attempted to do the Encoding of the tag name, such as as is returned from the function xmlencodename and also tried URL Encoding.

Here is our tag which returns nothing.

82TK1INV.OCTANE_R+M/2

We have also tried these encoded versions, still to no avail:

82TK1INV.OCTANE_R%2BM%2F2

82TK1INV.OCTANER_M_2

Any help on how to return the values with special characters in the tag name would be very helpful!

thanks,

Paul Mazeika

[Former Member · Accepted solution]

Wow those are some wicked tag names. Whoever came up with them should be spanked..

I would suggest trying tag alias as well. I think itu2019s your only hope as MII will puke on most of them. I had this problem with a customer that accidently created a series of tags with &nsbp characters at the front, and couldn't delete them out of their historian.

[Former Member · Accepted solution]

Wonder why MII can't be made to read from or write to such tags!

Happy New Year!

Chanti.

[Former Member · Accepted solution]

To Chianti's question of why can't/shouldn't MII work with those bizarre tag names...

Actually, there are a number of reasons:

1) It's a poor design practice to use characters like that in tag names, regardless of the underlying system. That type of information is best assigned to the tag description, not the tag name. I've even seen idiots put leading spaces on tag names...figure that one out!

2) MII uses XML extensively, and XML's syntax rules dictate what is and is not acceptable for XML element and attribute names, and many of these special characters are not permitted.

3) Usage of characters in tags that also represent mathematical operators greatly complicate the parsing and processing of expressions that involve tag names

In general, it reminds of the story of the guy who walks into the doctor, bangs his fist against a specific spot on his head, and says "Doc, it hurts when I do this", to which the doctor responds, "so don't do that".

So, Don't Do That.

[agentry_src · Accepted solution]

Paul,

I wholeheartedly (and enthusiastically) agree with Rick on all his points. Unfortunately, they probably don't help you much at this point.

I recommend going back to the PHD side of things and have calculated tags created to map directly to those which have invalid xml names. In general, do more with calculated tags at the historian level to save yourself a lot of headaches and maintenance problems. And your overall system performance will be better compared to other alternative solutions.

Unfortunately, most customers are reluctant to perform (or allow to be performed) such additions or changes to their historians.

Good luck, either way!

Mike

[former_member189057]

Thanks everyone for their responses. I ended up using aliases...although it seems we may be able to connect to PHD via OLEDB, which will also solve the issue.

Couple of points concerning the feedback:

1) The PHD system is not under control by the IT group here at our comapny, but by the Process Control group.

2) These tags were generated by an external system and imported to PHD.

3) No other systems that that the non-IT people use, such as ModTag, and other UniFormance tools from Honeywell have issues with these tag names. It is just xMII that has an issue.

Still no excuse, but just some background info.

thanks everyone,

Paul Mazeika

[former_member189057]

All-

We setup an alias, and that did work. Will use that as last resort.

But here is the kicker. We have an IP21 shadow system that gets its data from PHD, and that wierd tag name queries just fine from IP21, just not PHD [OPC HDA].

So it seems it is an issue with OPC-HDA UDS, but not with OLE DB UDS.

Do you think I should open an OSS Note with SAP on the issue?

thanks,

Paul

[jcgood25]

Do you have the latest update for the 4.0 UDS? Off the top of my head I don't know if any specific notes or patches addressed bizzare tag names, but it's worth looking into the notes. If you are running the latest version then I would suggest logging a customer ticket.

[former_member189057]

We have the 4.0.3.10 version of the UDS. Looks like latest version is 4.0.3.23.

We will install the latest on our sandbox and see if that does anything. If still no worky, will open an OSS.

thanks,

Paul

[former_member189057]

Hi All-

Thanks for the responses. I was hoping to avoid aliasing them, as now we have to maintain them in two places.

Will leave this open a little bit more, see if anyone from SAP has any advice.

Will award points soon.

thanks all,

Paul

[Former Member]

Any thoughts on creating an UDS alias in MII on the OPC server that allows you to change the name of the tag thus relieving your headache?