Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
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Use I/O Modules with CompactLogix 5370 L2 Controllers
Chapter 8
Power Supply Distance Rating
In a CompactLogix 5370 L2 control system, you can install Compact I/O
modules on as local expansion modules to the right of the controller system.
Compact I/O modules each have a power supply distance rating that you must
consider before you install them.
Power supply distance rating is the number of slots a Compact I/O module can
be installed away from the power supply. If a Compact I/O module has a distance
rating of three, you can include up to two modules between the Compact I/O
module and the power supply.
Additionally, the controller has embedded I/O modules that are designed to
protect against installation of a Compact I/O module directly to the right of the
embedded power supply. CompactLogix 5370 L2 control systems have
embedded I/O modules in the controller. CompactLogix 5370 L2 control
systems have one or two embedded
I/O modules as described as follows:
•
1769-L24ER-QB1B controller - One embedded I/O module
•
1769-L24ER-QBFC1B and 1769-L27ERM-QBFC1B controllers - Two
embedded I/O modules
The embedded I/O modules are not considered local expansion modules.
However, you must still include each embedded I/O module in the module slot
count when determining where to install Compact I/O module as a local
expansion module.
Because CompactLogix 5370 L2 control systems only allow up to four local
expansion modules in the system, you can install most Compact I/O modules in
any local expansion module slot. Some Compact I/O modules have power supply
distance ratings that affect where you can install them in the CompactLogix 5370
L2 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.
The farthest local expansion module slot where you can install one of these
modules in a CompactLogix 5370 L2 control system is module slot number two
or three as determined by the controller catalog number that is used in the
control system.
describes the farthest local expansion module slot where you can install
a 1769-HSC high-speed counter module and meet its power supply distance
rating requirement.
