User manual

Publication LOGIX-AP010B-EN-P - May 2010 51
Software Conversions - Program Structure Chapter 2
One of the first decisions in developing a Logix 5000 project is to define the
functions or operations of your machine or process.
1. Identify the major functions/operations of your machine or process.
2. For each function, choose the programming language that best fits the
function.
• This may require revising the functions list to take advantage of other
languages.
• Use any combination of the languages in the same project.
If the function or group of functions represent Use this language
Continuous or parallel execution of multiple operations
(not sequenced)
Ladder Logic (LD)
Boolean or bit-based operations
Complex logical operations
Message and communication processing
Machine interlocking
Operations that service or maintenance personnel must
interpret to troubleshoot the machine or process
Continuous process and drive control
Function Block Diagram (FBD)Loop control
Calculations in circuit flow
High-level management of multiple operations
Sequential Function Chart
(SFC)
Repetitive sequences of operations
Batch process
Motion control with structured text
State machine operations
Complex mathematical operations
Structured Text (ST)Specialized array or table loop processing
ASCII string handling or protocol processing