*Result*: Process control software specification in PCSL

*This paper presents the most important features of PCSL, a language to the specification of process control software. PCSL is primarily intended to improve software reliability. Simple structures of both active system components and data are supported by the language. Different constructs for static data, for dynamic data moving through the system (data flow), and for resources permit easy modeling of the situations common in process control applications. PCSL is accepted by an advanced, table-driven version of the well known PSA. As an example, a simple system for data collection is partially specified in PCSL. Finally, the current state is indicated, and limitations are discussed.*