I/O AllocationFP2/FP2SH3 − 33.1 Fundamentals of I/O Allocation3.1 Fundamentals of I/O Allocation3.1.1 I/O Allocation and RegisteringI/O allocation is the process of assigning an I/O number to each unit. Registering refersto registering the I/O allocations in the system register of the CPU.3.1.1.1 Types of I/O Allocation MethodsThere are 3 types of allocation methods: I/O mount allocation, arbitrary allocation, andautomatic allocation.I/O mount allocationUsing the programming tool software (NPST-GR/FPWIN GR), the allocation conditionof the mounted units is recorded, as is, to the system register of the CPU.Arbitrary allocationThe programming tool software (NPST-GR/FPWIN GR) is used to create I/O allocationsand register them in the system register of the CPU. In this case, no deviations in I/Onumbers will occur if a unit mounting error was made.Automatic allocationIf units are installed, allocation will take place when the power is turned on based onthe states of the installed units.NoteAutomatic allocation only assigns I/O numbers to mounted units.It does not register the allocations.3.1.1.2 Precautions Regarding Registering of I/O AllocationIf registering is not performed when using arbitrary allocation:Automatic allocation will be performed, and allocation will be based on the state of theinstalled units.If I/O registration has already been performed:If the registered information is different from the actual state of installation, such aswhen a unit is changed to a different type or the installation position is changed, normaloperation will not take place. In this case, perform registration once again.
