This paper deals with the employment of an Arm Exoskeleton as Haptic Interface in order to realize the simplest non trivial kind of force-based interaction which can help Virtual Environments (VE) operators in the completion of exploratory tasks i.e. the interaction of the operator hand with rigid bodies whose position in the VE is fixed. Our interest was to record operators behaviors and feelings and to determine the set of interactions which can be reproduced in a satisfactory way with our system. The experimental results show the influence of system sampling time and force generation model on the realism of contacting and following virtual surfaces.