Syntax of a directed event broadcast in an embedded Matlab function in Stateflow

Does anybody know the Syntax for a direct event broadcast in an embedded Matlab function called in Stateflow?

1.) As in stateflow the syntax is like: send(Ok, Pacer.Done)

2.) In the embedded Matlab function I am only able to broadcast the event "OK", which is an Undirected event Broadcast and will generate a Warning when executed. Writing in the code like send(Ok, Pacer.Done) or similar will produce a syntax error, as embedded Matlab does not know send(xx, yy) of Stateflow!

Nevertheless execution is fine and works, but the Warning is nasty!