Hello,

I am using WinCC Unified v19.

My goal now is to read the values of an HMI UDT tag inside a Faceplate using only the tagname passed  as a property interface.

Tag UDT (M_100) :

MotorTag is the Property Interface

tagname = Faceplate.Properties.MotorTag;

let actual_speed = Tags(tagname + ".actual_speed").Read();

HMIRuntime.Trace("#### " + actual_speed);

 Trace says

"session: 0002, trace: HmiTag: Tag 'M_100.actual_speed' does not exist"

So I am building the tag correctly but I cannot retreive the value from inside the faceplate.

What am I doing wrong?

Hello davide_capobianco,

Have you tried the following?

Tags("MotorTag.actual_speed").Read();

Hi MindFlyer,

thanks for the answer.

I have just tried Tags("MotorTag.actual_speed").Read() but it does not work.

Returns error: cannot find specified tag.

Hello davide_capobianco,

Can you upload your project and describe where the Faceplate is used?

Hi Murof,

what you say works for the interfaces but not for the properties of the faceplate

In my case MotorTag is a property and if_state is an interface.

You could say "Just use a string interface" and you are right but in version 19 Tag Interfaces cannot be declared as string (I cannot understand why).

So I tried to use Property Interfaces (that can be declared as string --multilingual or wstring --) as MotorTag name, and from this access to the fields of the Tag.

But seems that this is not supported.

Hi All,

I've found the way to do it, I write it down in case someone needs.

I just used an HMI UDT as interface tag. 

I can define a field of the UDT as WString and use this as name (for example motor name).

Probably this is the way that Siemens intended to use the faceplate, at least in V19