METHOD AND SYSTEMS FOR USE WITH AN INDUSTRIAL CONTROLLER

摘要

A method and system for generating a control program (25) executable by an industrial controller (20), wherein a source program (42) is displayed using a variable width ladder diagram (44). A ladder diagram (44) representative of at least one of the instructions of the source program is displayed on a display device (32). The ladder diagram comprises a graphical interconnection of schematic elements (102), at least one of which having a corresponding display width which is variable. The corresponding display width is varied in dependence upon the greater of a corresponding symbol display width (106) and a corresponding label display width (108). A method and system for data communication with the industrial controller uses a hybrid error detection code. Each transmitted packet of data (230) is augmented with either a Fletcher checksum code (234) or a CCITT-16 cyclic redundancy check code (236).