Formal modeling and analysis of the modbus protocol

Abstract

Modbus is a communication protocol that is widely used in SCADA systems and distributed control applications. This paper presents formal specifications of Modbus developed using PVS, a generic theorem prover; and SAL, a toolset for the automatic analysis of state-transition systems. Both formalizations are based on the Modbus Application Protocol, which specifies the format of Modbus request and response messages. This formal modeling effort is the first step in the development of automated methods for systematic and extensive testing of Modbus devices. © 2008 International Federation for Information Processin.