This module introduces the student to the fundamentals of tags and tag-based PLC programming. In addition to produced and consumed tags, the module also covers common methods for creating tags and explains the purpose of User Defined Data Types (UDTs). Theoretical areas of study include continuous and periodic tasks as well as the various types of data used in tag-based I/O systems. The principles of projects, arrays, throughput, and scope are described in detail, emphasizing practical applications and standard programming techniques.
Upon completion of this module the student will be able to:
- Differentiate between address-based and tag-based PLCs
- Describe the main elements of a tag
- Define the term scope and explain its purpose in a tag
- Explain the purpose of a User Defined Data Type (UDT)
- Name three types of arrays
- Define Produced and Consumed tags
- Differentiate between a continuous task and periodic task
- Explain the principles of Logix5000 I/O addressing
- Describe the four types of data used in tag-based I/O
- List three methods to increase throughput
- Explain why Add-On Instructions (AOIs) are used in PLCs.
- Describe the purpose of source protection in AOI applications.