Stand clear of the equipment, Program alteration, Safety circuits – Rockwell Automation 1769-IR6 Compact I/O 1769-IR6 RTD/Resistance Input Module User Manual
Page 82: Module operation versus channel operation

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Rockwell Automation Publication 1769-UM005B-EN-P - March 2012
Chapter 5 Diagnostics and Troubleshooting
Stand Clear of the Equipment
When troubleshooting any system problem, have all personnel remain clear of
the equipment. The problem could be intermittent, and sudden unexpected
machine motion could occur. Have someone ready to operate an emergency
stop switch in case it becomes necessary to shut off power.
Program Alteration
There are several possible causes of alteration to the user program, including
extreme environmental conditions, Electromagnetic Interference (EMI),
improper grounding, improper wiring connections, and unauthorized
tampering. If you suspect a program has been altered, check it against a
previously saved master program.
Safety Circuits
Circuits installed on the machine for safety reasons, like over-travel limit
switches, stop push buttons, and interlocks, should always be hard-wired to the
master control relay. These devices must be wired in series so that when any
one device opens, the master control relay is de-energized, thereby removing
power to the machine. Never alter these circuits to defeat their function.
Serious injury or machine damage could result.
Module Operation versus
Channel Operation
The module performs diagnostic operations at both the module level and the
channel level. Module-level operations include functions such as power-up,
configuration, and communication with a 1769 bus master, such as a
MicroLogix 1500 controller, 1769-ADN DeviceNet Adapter or CompactLogix
controller.
Channel-level operations describe channel related functions, such as data
conversion and over- or under-range detection.
Internal diagnostics are performed at both levels of operation. When detected,
module error conditions are immediately indicated by the module status
indicator. Both module hardware and channel configuration error conditions
are reported to the controller. Channel over-range or under-range conditions
are reported in the module’s input data table. Module hardware errors are
typically reported in the controller’s I/O status file. Refer to your controller
manual for details.