The Mitsubishi FX5-4AD-ADP is an analog input expansion adapter for the FX5 PLC family, providing four differential channels configurable for either ±10 V DC (1 MΩ input resistance) or ±20 mA DC (250 Ω burden). Each channel returns a 14-bit binary value to the CPU, with absolute maximum inputs of ±15 V and ±30 mA before damage. The adapter occupies zero I/O points on the PLC bus — it draws its power and data from the expansion connector without eating into the system's maximum I/O count.
Panel fit and wiring
Because the module claims no I/O points on the PLC's maximum limit (zero occupied points), it can be added even to a fully allocated rack without forcing an I/O count upgrade. This is a practical detail for panel builders who have already filled the CPU's I/O budget with discrete and other special-function modules.