Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 72)

Publication 1746-UM003A-EN-P
4-24 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) for the following conditions:
•
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 following reasons:
•
Input type is a 10
Ω
Copper RTD and the excitation current is set for 0.25
mA, which is not allowed.
•
Lead R Enable bits 14 and 15 are set to 11, which is invalid.
•
Broken Input select bits 6 and 7 are set to 11, which is invalid.
•
Data format bits are set to 11, and the lower limit user-set scale is equal to
the upper limit user-set scale and not equal to 0.
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).