o robot_info - This is the address of a robot_info_t structure initialized using mrd_startup(3mrd) or mrd_show(3mrd). This data structure contains the element starting address and counts for each type of element, which are needed to map an absolute element to the correct zero relative address and type. o port - The absolute integer element address of the port which is to be used as the destination of the move. o dev_status - The dev_status is the address of a dev_status_ t structure, which is used to pass back detailed error information in the event of a command failure.