What does the absolute I/O address identify on a PLC input module?

The absolute I/O address identifies the actual physical location of the input module on a programmable logic controller (PLC). This means that each input module is assigned a specific address that corresponds to its physical placement within the PLC system or rack. Understanding this physical address is crucial for the PLC to accurately read input signals from various sensors or devices connected to that input module.

By knowing the absolute I/O address, technicians and programmers can ensure that the PLC receives data from the intended input point, thereby facilitating correct operation and control of the entire system. This address helps the PLC to differentiate between multiple input modules and to interact with each one based on its specific physical position in the system structure.