Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
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Use I/O Modules with CompactLogix 5370 L3 Controllers
Chapter 9
Power Supply Distance Rating
CompactLogix 5370 L3 control systems do not have embedded I/O modules.
You begin counting local expansion slots with the first Compact I/O module
installed next to the power supply when determining where to install a
Compact I/O module and meet its power supply distance rating.
In CompactLogix 5370 L3 control systems, you can install Compact I/O
modules to the left or right side of the power supply. You can also use local and
extra banks in CompactLogix 5370 L3 control systems, with each allowing the
inclusion of Compact I/O modules.
Local Bank
In the local bank, the controller must be the leftmost device in the system and
you can only install up to three modules between the controller and the power
supply. Therefore, any Compact I/O modules that are installed to the left of the
power supply in the local bank, are in a module slot that meets the module’s
power supply distance rating requirements.
Additional Banks
CompactLogix 5370 L3 control systems also support the use of extra banks for
the local expansion modules of the system. Every additional bank requires a 1769
Compact I/O power supply. The bank can be designed with local expansion
modules on either side of the power supply.
Most Compact I/O modules have power supply distance rating values that allow
you to install them in any slot on either side of the power supply in extra banks.
Some Compact I/O modules have power supply distance ratings that affect
where you can install them in the CompactLogix 5370 L3 control system.
For example, the 1769-ASCII Compact ASCII and 1769-HSC Compact
high-speed counter modules each have a power supply distance rating of four.
These modules can be installed in local expansion module slots one
through three.
