[Solved] The surface of the device and heat sink may look perfectly flat to the naked eye. OFF Condition: A state or mode in which a system, circuit, or device is deactivated or not functioning. ON Condition: A state where a circuit is complete, allowing current to flow, or a logical condition that has been met. PLC Programming Languages: Languages developed to create programs for Programmable Logic Controllers, including Ladder Diagram, Function Block Diagram, and Structured Text. Graphical Language: A visual programming language where the user creates programs by manipulating graphical elements rather than writing textual code.