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Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
Chapter 6
Communicate over Networks
Power Supply Distance Rating
CompactLogix 5370 L2 and L3 control systems enable you to install 1769-SDN
scanners as local expansion modules. The 1769-SDN scanner has a power supply
distance rating that you must consider before installing it.
Power supply distance rating is the number of slots a 1769-SDN scanner can be
installed away from the power supply. The 1769-SDN scanner has a power supply
distance rating of four. Therefore, your CompactLogix 5370 L2 or L3 control
system can include up to three modules between the 1769-SDN scanner and the
power supply.
The power supply distance rating of the 1769-SDN scanner as a design
consideration differs by CompactLogix L2 controller catalog number.
CompactLogix 5370 L2 Control Systems
In a CompactLogix 5370 L2 control system, you can install a 1769-SDN scanner
on the right side of the control system. The controller has an embedded power
supply, which disallows the installation of 1769-SDN scanners between the
controller and the power supply.
Additionally, the controller has embedded I/O modules that disallow installation
of the 1769-SDN scanner directly to the right of the embedded power supply.
CompactLogix 5370 L2 control systems have one or two embedded I/O
modules, 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
While the embedded I/O modules are not considered local expansion modules,
you must still include each embedded I/O module in the module slot count when
determining where to install the 1769-SDN scanner as a local expansion module.
The farthest local expansion module slot where you can install the 1769-SDN
scanner 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-SDN scanner and meet its power supply distance rating requirement.
