Hello,
I am looking DD-files (drivers device) for measuring devices, for connecting via HART with FDM (DTM Honeywell).

Tell me where you can download.

I realized that for this you need to download the SITRANS DTM v.3 and then the EDD files of the instrument separately.

Are they compatible with Honeywell FDM R450?

DD's, EDD's, or DTM's driver files are only compatible for whatever specific device the driver is designed for AND for the software running the driver.

DD's are used by some software, DTM's are used by other software. 

For instance, Siemens PDM uses some form of DD (although it is not possible to load a manufacturer's DD into PDM).   PDM can not use a DTM file.

Pactware software uses DTM's not DD's.    Pactware can not run a DD file.  A DD file will not load in Pactware and will not run.

Google can't find a Honeywell R450.  Given that information, the answer is no, Siemens DTMs are not compatible with a device Google can not find.

What type of files does FDM use?   DD's?  DTM's?   something else (Honeywell has a reputation for proprietary communications, like DE).

What is a Honeywell R450?

It isn't clear to me why you're inquiring about a driver file for Honeywell's asset manager software, FDM (Field Device Manager), for an unknown Honeywell device (R450).   What is the Siemens connection?

Why so many negative emotions .

Link you need about FDM here it is GOOGLE

FDM works with DD files and DTM, of course compatible with FDM.