Analysis of Nested CRC with Additional Net Data in Communication

Abstract

Cyclic Redundancy Check (CRC) is an established coding method to ensure a low probability of undetected errors in data transmission. CRC is widely used in industrial field bus systems where communication is often executed through different layers. Some layers have their own CRC and add their own specific data to the net data that is meant to be sent. Up to now, this nesting is not yet included in the safety proof of systems. Hence, additional effort is made to achieve a required degree of safety which was probably on hand but could not be proven. The paper presents an approach to involve the nesting in the calculation of the residual error probability based on methods of coding theory. This approach helps to reduce the number of worst case assumptions in the overall safety proof and finally to reduce the necessary online efforts like the number of parity bits.KeywordsCyclic Redundancy CheckResidual error probabilitySafety-critical communication