As M. Dahlhausen has pointed out in Question on Results Visualization, EMS can be run with OpenStudio.
I did not, however, find any EMS measure at online BCL. Furthermore, many of my EMS controls use Constant Schedules (to be modified during simulation), but apparently it is not possible (or obvious how to) create Constant Schedules in OpenStudio.
Hence my question: How do you EMS with OpenStudio ? Do you need to be a programmer (using the API) ?