Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 35)

Publication 1785-UM012D-EN-P - July 2005
Selecting and Placing I/O 2-3
Placing I/O Modules in a
Chassis Place I/O modules in a chassis depending on the electrical characteristics of
the module. The placement is made left to right, with the left-most position
being closest in the chassis to the PLC-5 controller or the I/O adapter module.
The placement order is as follows:
Place input and output modules according to
these guidelines:
left to right
lowest voltage to highest voltage
For optimal speed using discrete I/O, use the
following module-placement priority scheme:
1. controller chassis
2. extended-local I/O chassis
3. remote I/O chassis
Place block-transfer modules according to these guidelines:
Place as many modules as possible for which you need
fast block-transfer times in your controller-resident local
I/O chassis.
Place modules in which block-transfer timing is not as
critical in remote I/O chassis.
Ac output modules should always be the furthest I/O
modules away from any block-transfer modules in the
same chassis.
P
L
C
/
A
S
B
Block
Transfer Block
Transfer dc
input dc
input dc
output dc
output ac
input ac
input ac
output ac
output
1 Priority: 2 1 2 3 3 4 4 5 5
lowV highV
Module placement priority:
1. block-transfer modules (all types)
2. dc input modules
3. dc output modules
4. ac input modules
5. ac output modules
empty