The experimental physics and industrial control system (EPICS) is being used to develop a measurement and control system for the advanced free-electron laser (AFEL) at the Los Alamos National Laboratory. EPICS is an integrated system of applications development tools and a distributed run time environment that supports an input-output database, a graphical operator interface, sequential control through "state" definition, data archiving, data analysis, and fault management. It is very advantageous in terms of both time and system integrity to be able to perform much of the control system development before the actual hardware for the AFEL is in place. Using the EPICS applications tools, we are developing prototype measurements and controls that can be directly transferred to the AFEL during installation and commissioning. This is possible due primarily to three aspects of EPICS. First, we can easily model physical systems with the state notation language. Second, we can simulate input and output channels with "soft" database channels, which are created using the database configuration tool. Third, we can easily build and modify operator interface screens with the display editor.
