Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 143)

Publication 1756-UM009C-EN-P - December 2010 143
Temperature-measuring Analog Modules (1756-IR6I, 1756-IT6I, and 1756-IT6I2) Chapter 6
Module Fault Word Bits – Floating Point Mode
Bits in this word provide the highest level of fault detection. A nonzero
condition in this word reveals that a fault exists on the module. You can
examine further down to isolate the fault.
The table lists tags that are found in the Module Fault Word.
Channel Fault Word Bits – Floating Point Mode
During normal module operation, bits in the Channel Fault word are set if any
of the respective channels has an Under or Overrange condition. Checking this
word for a nonzero value is a quick way to check for Under or Overrange
conditions on the module.
The table lists the conditions that set all Channel Fault word bits:
Your logic can monitor the Channel Fault Word bit for a particular input to
determine the state of that point.
Module Fault Word Tags
Tag Description
Analog Group Fault This bit is set when any bits in the Channel Fault word are set.
Its tag name is AnalogGroupFault.
Input Group Fault This bit is set when any bits in the Channel Fault word are set.
Its tag name is InputGroup.
Calibrating This bit is set when any channel is being calibrated. When this
bit is set, all bits in the Channel Fault word are set. Its tag
name is Calibrating.
Calibration Fault This bit is set when any of the individual Channel Calibration
Fault bits are set. Its tag name is CalibrationFault.
Cold Junction
Underrange – 1756-IT6I
and 1756-IT6I2only This bit is set when the ambient temperature around the cold
junction sensor is below 0
o
C. Its tag name is CJUnderrange.
Cold Junction Overrange
– 1756-IT6I and
1756-IT6I2only This bit is set when the ambient temperature around the cold
junction sensor is above 86
o
C. Its tag name is CJOverrange.
Channel Fault Word Conditions
This condition sets all Channel
Fault word bits And causes the module to display the
following in the Channel Fault word bits
A channel is being calibrated. “003F” for all bits
A communication fault occurred
between the module and its
owner-controller. “FFFF” for all bits.