The method you describe is very similar to Telegrams with Sinamics drives, with the minor exception that with Starter / Portal (or Classic Step 7), the scaling is predefined in the drive with a "function diagram" showing the model Siemens uses for scaling Word (or sometimes, Real) data from / to the PLC.

I noticed in the same section of the linked .pdf in those same pages the same information as you found.  I stopped looking at that point, but felt sure Parker had built something that could be modified in some way to allow generic data transfer.

It is too bad the existing Parker FB for their module does not suit your needs, especially considering they only show support for 3 different types of telegrams.

FOrNExt00

Zivilin

In my experience, sending REAL (floating point) values directly is pretty rare in such devices. I browsed through the materials found in the link given by jacek, and found the section about communication which I would use as my starting point for creating a device-handling FB (see attachment, left side).

Immediately I see that in direct positioning mode, I will be sending three variables - a control word (STW1), a velocity setpoint (XSOLL_A) and a position setpoint (XNOM_A). Crucially, the analog values do not seem to be floating point, but 3 decimal places fixed point variables, so an integer value of, say, 1234 is sent to the servo is interpreted as a real value 1.234.

The attachment (right side) shows how I would go about constructing a basic servo-handling DB. I threw in some examples of splice access, which makes it easier to access individual bits of a word or swap bytes without resorting to shift registers. More information on splice access in the link below.

How can you access unstructured data types bit-by-bit, byte-by-byte or word-by-word and symbolically in STEP 7 (TIA Portal)? 

Let's tell the whole story. This drive use module T40 for electronic CAM (don't ask why we use parker with simatic PLC). This module give ability to write code inside parker drive in CodeSys v2 base environment.  The servo is controlled by simple wire IO on it's input module (speeds, pos and other params are predefined  - hardcoded in servo ). We need only to change the CAM ration - and here comes the REAL numbers I want to send over Profinet. 

I found this manual . On page 462 is define Profinet communication. Now (finally) on 470 the data types are define. I saw that data type of Long Int (doble word) is the same like in S7-1200 data type DINT.

I will use  your idea. Before send something to servo I will scale it UP (Real * ScaleFactor -> DINT), and in the servo (I can write code there) I will scale it down (DINT -> REAL / ScaleFactor). It what way I think I, can address the IO image in PLC by definition of Tags (again like you show me in the first post - Plan A). 

Hope this works - will be glad to hear another opinion.