Which of the following is NOT a type of PLC language?

The choice of Flowchart diagram as the option that is NOT a type of PLC (Programmable Logic Controller) language is correct because PLC programming languages are specifically designed for automation and control tasks. Instruction List, Structured Text, and Ladder Diagram are all recognized as standard IEC 61131-3 programming languages used in the development of PLC systems.

Instruction List is a low-level language that allows programmers to write code in a concise manner, similar to assembly language. Structured Text is a high-level text-based language that is more akin to traditional programming languages, providing advanced data handling capabilities and complex control structures. Ladder Diagram, resembling electrical relay logic diagrams, uses symbols to represent control logic visually, making it easier for engineers and technicians to understand the control processes.

In contrast, a Flowchart diagram is a visual representation of a process but does not conform to the specifications of programming languages used in PLCs. While flowcharting is a valuable tool for planning and outlining processes and algorithms, it does not serve as a programming language that a PLC uses to execute control functions. This distinction makes Flowchart diagram the correct answer in identifying what is NOT categorized as a PLC language.