Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 44)

Assigning Addressing Modes,
Racks, and Groups
Chapter 4
4-2
The following guidelines are for placing block-transfer modules.
Place as many modules as possible for which you need fast
block-transfer times in your processor-resident local I/O chassis .
Place modules that need fast block-transfer times (but space is not
available in processor-resident local I/O chassis) in an extended-local
I/O chassis.
Place modules in which timing is not as critical as in other
block-transfer modules in remote I/O chassis.
ac output modules should always be the furthest I/O modules from any
block-transfer modules in the same chassis.
Become familiar with the following terms and their definitions:
An I/O group is an addressing unit that corresponds to an input
image-table word (16 bits) and an output image-table word (16 bits). An
I/O group can contain up to 16 inputs and 16 outputs; and it can occupy 2-,
1-, or 1/2-module slots for addressing purposes.
00
01
02
03
04
05
06
07
10
11
12
13
14
15
16
17
00
01
02
03
04
05
06
07
10
11
12
13
14
15
16
17
00
01
02
03
04
05
06
07
10
11
12
13
14
15
16
17
13073 (I/O Group #0) (I/O Group #0)
2ĆSlot I/O Module Group 1ĆSlot I/O Module Group
Input
Terminals
Output
Terminals
Output or
Input
Terminals
Understanding the Terms
Used in this Chapter