EtherCAT devices with Modular Device profile (MDP) are supported in SYCON.net / EtherCAT Generic Slave DTM. The issue with such device we know of at present is for example BK1120 from Beckhoff.
Beckhoff maintains to sets of DDs (ESI XMLs) for its bus coupler devices. The newer one and usable in third party engineering tools like SYCON.net are tagged with MDP (Modular Device Profile).
In order to get these XML files, customer should contact ETG, precisely Mr. Florian Essler, f.essler@ethercat.org.
When having these files, mostly zipped, unpack and find a subfolder "Beckhoff_BKxxxx (MDP)" which contains MDP version of couplers' descriptions and Modules ESI XMLs in further subfolder "Beckhoff BKxxxx MDP".
For SYCON.net you need "Beckhoff_BKxxxx (MDP)\Beckhoff BKxxxx MDP.xml" and "Beckhoff_BKxxxx (MDP)\Beckhoff BKxxxx MDP\BKxxxxModules.xml" to be imported as EtherCAT XMLs.
I would recommend that previously installed XML file "Beckhoff BKxxxx.xml" is removed from the installation (on Win 7: "C:\ProgramData\SYCONnet\EtherCat\DDF\Beckhoff BKxxxx.xml") in order to reduce the devices number in the catalog with many confusing entries for BK1120 e.g.
We have 2013 version of this MDP files se:
Screenshots below are showing the use of the Beckhoff MDP and modules XML files.
You'd need new version of the Beckhoff MDB files set for BK1120 as the old one doesn't include definitions for newer KL1408 and KL2408 module for example.