What is a key characteristic of the XIC instruction in PLC programming?

The XIC instruction, which stands for "Examine If Closed," is a fundamental element in PLC programming. It is primarily used to check the status of an input device or a control variable. A key characteristic of the XIC instruction is its ability to be connected in series with other commands. This aspect allows it to facilitate complex control logic by enabling multiple conditions and instructions to be evaluated in a sequence. When XIC instructions are linked together, they ensure that certain conditions must be true for the subsequent instructions to execute. This capability is critical for designing intricate automation processes where many inputs need to be validated before actions can be taken.

While the XIC does evaluate the status of input devices or control variables, suggesting that it can only be used for input devices (the first choice) is overly limiting. The second choice, which mentions the requirement of a control variable, does not accurately capture the full functionality since it can evaluate a direct input condition as well. Moreover, the option that states it activates multiple outputs simultaneously is misleading; the XIC instruction itself does not activate outputs but rather influences the control flow based on the conditions being met.

Thus, the ability to connect XIC instructions in series with other commands underscores a fundamental aspect of PLC programming, allowing