Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules User Manual

Page 64

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64

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 3

Common Module Features

Use the Module Properties dialog box in RSLogix 5000 software to determine if
the module has been synchronized with the owner-controller and whether the
controller is synchronized with the CST. For more information on synchronizing
owner-controllers and modules with the CST, see the ControlLogix System User
Manual, publication

1756-UM001

.

Fault and Status Reporting
between Input Modules and
Controllers

ControlLogix digital input modules multicast fault and status data to any owner-
controller or listening controller. All input modules maintain a module-fault
word, the highest level of fault reporting.

The table lists the fault word and the associated tag that can be examined in
program logic to indicate when a fault has occurred for a standard input module.

All words are 32-bit, although only the number of bits appropriate for each
module’s density are used. For example, the 1756-IA16I module has a module-
fault word of 32 bits. But, because this is a 16-point module, only 16 bits (0…15)
are used in the module-fault word.

The following illustration offers an overview of the fault reporting process on
ControlLogix standard digital input modules

.

Table 4 - Fault Word on Input Modules

Word

Tag Name

Description

Module-fault

Fault

Provides fault summary reporting. Available on all digital input
modules.

Table 5 - Bits Set in Module-fault Word

Condition

Bits Set

Communication fault

All 32 bits are set to 1, regardless of the module’s density.

Module-fault Word

All Modules

42676

Bit 31

Bit 0

A communication fault sets all bits in the module-fault word.

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