Franca can be mapped to UML. The Franca UML mapping is specified in the YAMAICA Franca UML Mapping Guideline.
For the [http://www.sparxsystems.com/ Sparx] Enterprise Architect UML tool the YAMAICA Franca2EA feature is an implementation which supports this mapping guideline to perform transformations from Franca IDL to UML and vice versa.
Currently those transformations may be chained. This means the output of the transformation may be used as input for another transformation cycle, but there is no real round trip capability existing right now.
See YAMAICA Home for source code repositories and Eclipse update site links.