Allen-Bradley Compact GuardLogix 5370 User Manual

88 Rockwell Automation Publication 1769-UM022C-EN-P - June 2018
Chapter 6 Add and Configure Standard I/O Modules
Module Fault Related to RPI Estimates
When following the guidelines described in Table 9, most Compact
GuardLogix 5370 controller systems operate as expected. Some systems that
follow the guidelines can experience a Module RPI Overlap minor fault as
described in Table 10
.
Table 10 - Module RPI Overlap Fault
Name
Fault
Information Condition In Which Fault Occurs
Module
RPI
0verlap
(Type 03) I/O fault
(Code 94) Module
RPI overlap
detected
Module Slot = x,
where x is the slot
number of the I/O
module in the I/O
configuration
section
This fault is logged when the current RPI update of an I/O module overlaps with
its previous RPI update. The Minor Faults tab in the Controller Properties dialog
box indicates in which module the RPI overlap occurs.
If multiple I/O modules experience the fault, the application indicates that the
fault occurred on the first such I/O module. Typically, it is an I/O module with a
large I/O array sizes. Example modules that use large I/O array sizes include the
1769-SDN and 1769-HSC modules. In these cases, we recommend that you adjust
the RPI of the module to remove the fault.
Once the fault is cleared from the first I/O module, the application indicates the
next module that experiences the fault. This pattern continues until the fault is
cleared from all affected I/O modules.
To avoid this fault, set the RPI rate of the I/O modules to higher numerical values.
We recommend you use an RPI value that is not a common multiple of other
module RPI values, such as 2.5 ms, 5.5 ms, or 7 ms.
• We recommend that you do not run Compact GuardLogix 5370 controller
systems with Module RPI Overlap faults.
• A system that experiences many Module RPI Overlap faults cannot operate
optimally because I/O data is not sampled at the expected rate that the RPI
settings determine.
• When the project is downloaded or the RPI value of an I/O module is adjusted,
it is expected to have a minor fault. Faults under these conditions are
transitionary. Clear the fault and wait for the fault to reappear before
adjusting the RPI value or the task priorities.

Allen-Bradley Compact GuardLogix 5370 Specifications

General

Brand	Allen-Bradley
Model	Compact GuardLogix 5370
Category	Controller
Language	English