🔍 Key Concepts

• Look at the data type written beside the IN terminal in figure "B" (for the TOF timer); notice it also appears on Q and is labeled BOOL. • Recall what a Boolean (BOOL) signal means in PLC/IEC logic compared to analog and general digital signals. • Think about how a timer ON/OFF input is normally used in ladder or function‑block diagrams – is it continuously variable, or just ON/OFF?.

💭 Think About

• Ask yourself: if the input type is BOOL, how many distinct values can it have, and what are they usually called in PLC logic? • Compare the words "integer", "analog", "binary", and "digital" in the answer choices: which one most precisely matches a BOOL-type signal that can only be ON or OFF? • Consider whether a BOOL input could ever directly accept a multi-bit numerical value (like 37) or a varying voltage level, or if it is limited to a single bit state.

✅ Before You Answer

• Verify what BOOL stands for in IEC/PLC data types and how many states it has. • Confirm that the IN and Q terminals on block B both specify BOOL, meaning the input and output must be the same ON/OFF type. • Eliminate any options that would allow more than two possible values or a continuously varying value at the IN terminal.