What does the "Local:0:I" tag represent in a ControlLogix system?

The "Local:0:I" tag in a ControlLogix system refers specifically to Input Data. This tag format indicates a local scope input module, in this case from the local I/O. The "Local:" prefix signifies that the data is associated with a module that is physically present in the local chassis of the ControlLogix controller. The "0" following the colon identifies the slot number where the input module is located, while the "I" indicates that the data represents inputs.

In a typical ControlLogix I/O configuration, local input data is used to read data signals from the connected field devices, such as sensors or switches. Proper understanding of this tag is crucial for programmers, as it assists in effectively accessing and managing input data used in the control processes of an automated system.

Understanding the distinction between types of data is important for programming logic, as it directly influences how the system interacts with hardware. Other types of data, such as Configuration Data, Output Data, and Status Data, serve different purposes and are accessed through their respective tags, which would not be formatted as "Local:0:I."