control an opening of an accessory in the assembly design

Dear Community. 
I created an accessory in Equipment Design (a chuck) and I wonder if it is possible to control the opening of the jaws in Assembly Design (and lock it in position). I am asking this because I want to design "my machining setup" with the app Assembly Design  but I have the impression that the opening command is only possible if the accessory is put in a machining application.
Great Thank's to you all