In I/O wiring, what should you verify according to the I/O address assignment document?

Verifying that all I/O modules are in the correct locations is essential because proper placement of these modules ensures that the control system accurately reads data and sends commands. Each I/O module is assigned a specific address in the system, and if modules are incorrectly placed, it can lead to miscommunication between the hardware and the control system. This misalignment can cause incorrect readings, malfunctioning of processes, or failure of the system to operate as designed. Proper I/O address assignment ensures that signals are received and processed accurately, which is critical for the safety and efficiency of the instrumentation and control system.

The other options, while also important aspects of system integrity, do not directly relate to the verification of I/O addressing. For instance, ensuring all connections are secure and verifying the functionality of the power supply are crucial for overall system operation, but they do not specifically address the correct configuration of I/O modules as outlined in the I/O address assignment document. Similarly, keeping firmware updated is vital for optimal performance and security, but it is not directly tied to the physical placement of the I/O modules as presented in the question.