Rockwell Automation 1794-ASB/E Remote I/O Adapter Module User Manual - Manual (Page 37)

3–3 Communicating with FLEX I/O Modules
Publication 1794ĆUM009D-EN-P - April 2004
Complementary
•
you don't need full FLEX I/O module
functionality, including combination
modules (1794ĆIB10XOB6), settable
input delay times on input modules
(1794ĆIB16, ĆIB8S), and fuse blown
indication (1794ĆOB8EP), for
example.
•
you can locate equal numbers of
input and output modules in
separate chassis
•
Eight 8 point modules in each chassis
equal 1/2 logical rack (when input
modules are installed in 1 chassis, and
output modules are installed in the
complementary chassis).
•
Eight 16 point modules in each chassis
equal 1 logical rack (when input modules
are installed in 1 chassis, and output
modules are installed in the
complementary chassis).
•
Provides maximum use of I/O image table
in 2 FLEX chassis (when input modules
are installed in 1 chassis, and output
modules are installed in the
complementary chassis).
•
You must configure all modules
in both chassis as either 8Ćpoint
or 16Ćpoint.
•
No combination modules
allowed
•
Configuration/status data is not
accessible to user
Standard - 32
•
you need full FLEX I/O module
functionality, including 32 point
modules, combination modules
(1794ĆIB10XOB6), settable input
delay times on input modules
(1794ĆIB16, ĆIB8S), and fuse blown
indication (1794ĆOB8EP) for
example.
•
User has access to 2 words of input, 2
words of output for each digital module.
•
Four modules equal 1 logical rack.
•
No restrictions on module placement
•
Maximum use of configuration/status and
combination modules
•
Inefficient I/O image table
utilization
Complementary - 32
•
you don't need full FLEX I/O module
functionality, including combination
modules (1794ĆIB10XOB6), settable
input delay times on input modules
(1794ĆIB16, ĆIB8S), and fuse blown
indication (1794ĆOB8EP), for
example.
•
you can locate equal numbers of
input and output modules in
separate chassis
•
Eight modules in each chassis equal 2
logical racks
•
Provides maximum use of I/O image table
in 2 FLEX chassis (when input modules
are installed in 1 chassis, and output
modules are installed in the
complementary chassis).
•
All digital I/O modules are
configured as 32Ćpoint.
•
No combination modules
allowed
•
Configuration/status data may
not be accessible to user
(depending on module type).
The amount of data accessible to the processor in the 5 addressing
modes is illustrated below. Note that the shaded areas represent data
not accessible by the processor.