Software in a computer which accesses one or more software-intensive devices, such as a digital copier or printer, is organized in a set of layers. A device-dependent layer converts data transferred over various means, such as a modem or network, to a uniform data format. A protocol layer converts data from a particular accessed machine to a set of function calls. A system interface associated with the computer restricts a user of the computer to seeing only a subset of function calls, depending permissions granted to a particular user. The modular architecture of the software enables a system administrator to restrict a user to viewing machine status for a specific set of machines on a network, or limits the user to viewing only a certain set of functionalities from a particular machine.