A drive device for a sliding door system having a transom and at least one door leaf guided along the transom. The drive device includes: a housing which can be mounted on the transom; a pulley which can be driven in rotation by a drive, the pulley being mounted for rotation on the housing and having a flange with locking elements adjacent to the housing; an endless traction mechanism guided around the pulley for moving the at least one door leaf linked to the traction mechanism; complementary locking elements which can be moved relative to the housing to engage the locking elements on the flange and thereby prevent rotation of the pulley; and an electromechanical actuation device which moves the complementary locking elements in response to an impulse emitted by a locking control.