As you can see at http://www.intersystemsbenelux.com/media/media_manager/pdf/1398.pdf, Ensemble does not natively support ebRIM, but it does support XML and XML schemas. Maybe you could assemble an XML and use that to wrap your blob content.
You can send that over whatever protocol your XDS system provides (xDBC, SOAP, file system etc). Take a look at the items listed on sections "Ensemble Interoperability" and "Ensemble Adapter and Gateway Guides" of http://docs.intersystems.com/ens20122/csp/docbook/DocBook.UI.Page.cls for a full list of connectivity options.
Regards,