Communication between Upper Computer and Allen-Bradley-PLC through a Tyre-building Control

This paper analyzes the communication between Allen-Bradley (AB) series PLC logix5550 and the upper computer through calls by RS Linx C SDK in DELPHI. Based on I/O address distribution and differentiation, we put forward a mapping address method. The method can be used to solve problems in communication between PC and PLC. The method overcomes the limitation that PLC can only match the set kind of touch screen. It greatly increases the flexibility of hardware and significantly reduces the costs.