5 Operation
5-18
CJ-series PROFINET IO Controller Unit Operation Manual for NJ-series CPU Unit (W511)
Additional Information
Disabling Auto Addressing has no immediate effect on an existing I/O mapping.
I/O Mapping Without Auto Addressing
A disabled Auto Addressing feature has the following effects on I/O mapping.
•
When adding new IO Devices or new I/O modules to an existing configuration, the I/O mod-
ules will be mapped to the first I/O areas but the modules will be appended to the existing I/O
mapping.
•
When deleting a IO Device from the network configuration or deleting I/O modules from a IO
Device, the deleted I/O modules will leave gaps in the already existing I/O mapping. If after
deleting an I/O module, a slave device still has more than one module configured but these
modules are not in the same place, the DTM will attempt to re-map them together.
•
Changing the address of a IO Device, of which already an I/O mapping exists, has no effect
on the existing mapping.
•
Selecting an additional I/O module for a IO Device in the presence of already allocated I/O
modules will cause a complete re-map of all existing modules if the total I/O does not fit within
the space it is already occupying. The modules are re-mapped to the next available location
in the area leaving behind a gap in the existing I/O mapping. Subsequent I/O modules of
other slave device will remain mapped as before the module addition.
•
When moving an I/O module from one area to another they can be located anywhere with in
the target area. They are not re-mapped to the start of that area.
•
When moving an I/O module from one area to another the module leaves a gap in the I/O
mapping of the first area.
Additional Information
•
Gaps in the I/O mapping still contribute to the total size of an area, although they do not con-
tain valuable data. Therefore, they decrease the total I/O capacity of the CJ1W-PRM21 PRO-
FIBUS Master Unit and unnecessarily occupy CPU memory.
•
In the I/O data exchange with the CPU these gaps will contain zeros.
Example
The figure below illustrates the effects of re-allocating I/O modules when Auto Addressing has been
disabled.
