EXPERIENCE WITH THE STATE NOTATION LANGUAGE AND RUN-TIME SEQUENCER

The State Notation Language (SNL) has gained wide acceptance as a cont rol system development tool. The SNL uses a subset of C with additiona l control statements that are based on the state transition diagram pa radigm. In conjunction with a run-time sequencer, the SNL offers progr amming simplicity without significant performance penalty. As one of t he major tools in the Experimental Physics and Industrial Control Syst em (EPICS), the SNL has been successfully used on several control syst ems in a wide variety of applications, such as machine sequencing oper ation of beam diagnostics and facilitating complex operator interface functions. This paper presents the results of a survey of the various users of the SNL. The intent is to judge how well the SNL has met its original objectives and to determine future improvements. Such improve ments will include implementing a graphical sequencer builder and prov iding a comprehensive graphical debugging tool.