Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 35)

Chapter
Addressing I/O
3
3Ć6
When planning your system design, consider the densities of the I/O
modules you are using and choose an addressing mode that most
efficiently uses processor memory.
Choose the addressing mode for each I/O chassis by setting the chassis
backplane switch assembly.
Addressing Summary
Addressing
Mode:
Guidelines:
2Ćslot • Two I/O module slots = 1 group
• Each physical 2Ćslot I/O group corresponds to one word (16 bits) in the input image table and one word
(16 bits) in the output image table
• When you use 16Ćpoint I/O modules, you must install as a pair an input module and an output module in
an I/O group; if you use an input module in slot 0, you must use an output module in slot 1 (or it must be
empty). This configuration gives you the maximum use of I/O.
• You cannot use a blockĆtransfer module and a 16Ćpoint module in the same I/O group because
blockĆtransfer modules use 8 bits in both the input and output table. Therefore, 8 bits of the 16Ćpoint
module would conflict with the blockĆtransfer module.
• You cannot use 32Ćpoint I/O modules.
1Ćslot • One I/O module slot = 1 group
• Each physical slot in the chassis corresponds to one word (16 bits) in the input image table and one
word (16 bits) in the output image table
• When you use 32Ćpoint I/O modules, you must install as a pair an input module and an output module in
an even/odd pair of adjacent I/O group; if you use an input module in slot 0, you must use an output
module in slot 1 (or it must be empty). This configuration gives you the maximum use of I/O.
• Use any mix of 8Ć and 16Ćpoint I/O modules, blockĆtransfer or intelligent modules in a single I/O chassis.
Using 8Ćpoint modules results in fewer total I/O.
1/2Ćslot • One half of an I/O module slot = 1 group
• Each physical slot in the chassis corresponds to two words (32 bits) in the input image table and two
words (32 bits) in the output image table
• Use any mix of 8Ć, 16Ć, and 32Ćpoint I/O or blockĆtransfer and intelligent modules. Using 8Ćpoint and
16Ćpoint I/O modules results in fewer total I/O.
Block-transfer modules occupy 8 bits in the I/O image table. Since all
block-transfer modules are bidirectional, they cannot be used to
complement either input or output modules.
To address: use the:
singleĆslot modules assigned I/O rack and group number of the slot in which the
module resides and 0 for the module number
When using 1/2Ćslot addressing, use the assigned rack number
and the lowest group number and 0 for the module number.
doubleĆslot modules assigned rack number and the lowest group number and 0 for the
module number
Addressing BlockĆTransfer
Modules