Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
165
Use I/O Modules with CompactLogix 5370 L1 Controllers
Chapter 7
Empty Slots and Removal and Insertion Under Power Situations
The POINT I/O system cannot detect an empty terminal base. For this reason,
there are numerous situations in which you can potentially configure a system
that is unusable or one that exercises unintended control.
Follow these rules for I/O system configuration and RIUP of I/O modules.
•
A correct I/O system does not have any empty terminal bases. If necessary,
you can use a 1734-ARM POINT I/O Address Reserve module to replace
a 1734 POINT I/O module in a CompactLogix 5370 control system.
•
After you cycle power, the controller only enables I/O connections if the
number of local expansion modules present on POINTBus matches the
value that is used for the Expansion I/O parameter in the project.
•
If a 1734 POINT I/O module is removed under power, the operation of
the other I/O modules is not disrupted.
•
When you remove an I/O module that has an active connection from the
controller, the controller I/O status indicator flashes green to indicate the
condition.
•
If multiple contiguous modules are removed under power, connections to
all modules in the contiguous missing module set are disallowed until all
modules are replaced. The controller cannot detect an empty base.
Therefore, it does not know the physical positioning of the modules until
all missing modules are replaced.
•
If a module that separates two sets of contiguous missing modules is
removed, the two sets merge into one set. All modules must be replaced
before connections are permitted to any module in the set.
WARNING:
If you insert or remove the module while backplane power
is on, an electrical arc can occur. This could cause an explosion in
hazardous location installations.
Be sure that power is removed or the area is nonhazardous before
proceeding.
IMPORTANT
1734 POINT I/O modules support RIUP in CompactLogix 5370 L1
control systems.
IMPORTANT
If you enabled the 'Major Fault On Controller If Connection Fails While
in Run Mode' parameter when configuring the module in the Studio
5000® environment project, removal of the module causes the
controller to transition to a major fault condition.
