Rockwell Automation AADvance Controller Solutions Handbook - Manual (Page 83)

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Document: 553631
(ICSTT-RM447J_EN_P) Issue: 09:
5-3
Dual I/O Channel Capacity
When you need I/O modules arranged in dual redundant formations, each pair of
modules shares a dual termination assembly and occupies two-thirds of an I/O base
unit. The termination assemblies can bridge adjacent I/O base units, so two base units
will hold three pairs of dual redundant module configurations, while three base units
will hold four pairs. Arrange base units in groups of two or four to optimize capacity
for dual redundant modules.
If you arrange base units in groups of two or four, a single controller supports 24 pairs
of I/O modules. The capacity using for example eight pairs of 16-channel input modules
and sixteen pairs of output modules is 256 I/O channels (8 x 16 = 128, 16 x 8 = 128).
The capacity using 8-channel modules throughout in dual configurations (24 pairs) is 24
× 8 = 192 I/O channels. This might, for example, represent 64 digital inputs, 64
analogue inputs and 64 digital outputs, or any combination of these values with a
granularity of eight, the capacity of one I/O module.