Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 86)

Publication 1746-UM008B-EN-P - December 2006
86 Channel Configuration, Data, and Status
Out-of-range Error (Bit 14)
This bit is set (1) whenever a configured channel detects an
over-range condition for the input channel data, regardless of input
type. This bit is also set (1) whenever the module detects an
under-range condition when the input type is an RTD. An
out-of-range error is declared for either of the following conditions:
• over-range - The RTD temperature is greater than the maximum
allowed (default or user-set) temperature or the resistance input
type is greater than the maximum allowed (default or user-set)
resistance. When this occurs, the channel data word is set to its
maximum value.
• under-range - The RTD temperature is less than the minimum
allowed (default or user-set) temperature. When this occurs, the
channel data word is set to its minimum value.
This bit is cleared (0) when the:
• channel is disabled.
• channel operation is normal, the out-of-range condition clears.
• broken input error bit (bit 13) is set (1).
Configuration Error (Bit 15)
This bit is set (1) whenever an enabled and configured channel
detects that the channel configuration word is not valid. A
configuration word is not valid for any of the these reasons.
• Input type is a 10 Ω Copper RTD and the excitation current is set
for 0.5 mA, which is not allowed.
• Scaling select bits 13 and 14 are set to 11, which is invalid.
• Broken Input select bits 6 and 7 are set to 11, which is invalid.
• Scaling select bits 13 and 14 are set to 01 or 10 and scaling limit
words=0.
• Data format bits are set to 11, the scaling-select bits are set to 01
or 10 and the lower limit user-set scale word is greater than or
equal to the upper limit user-set scale word.
All other status bits reflect the settings from the configuration word
(even those settings that may be in error). However, bit 15 is cleared if
the channel is disabled or if channel operation is normal.
IMPORTANT
There is no under-range error for a direct resistance input
(default scaling).