Chapter 5
Channel Configuration, Data, and Status
5–23
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.
Important: There is no under–range error for a direct resistance input
(default scaling).
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 0.5
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.
Summary of Contents for SLC 500 1746-NR4
Page 1: ...User Manual SLC 500t RTD Resistance Input Module Cat No 1746 NR4 Allen Bradley AB Spares ...
Page 15: ...Preface P 8 Notes AB Spares ...
Page 37: ...Chapter 2 Quick Start 2 12 Notes AB Spares ...
Page 63: ...Chapter 4 Preliminary Operating Considerations 4 12 Notes AB Spares ...
Page 87: ...Chapter 5 Channel Configuration Data and Status 5 24 Notes AB Spares ...
Page 107: ...Chapter 7 Module Diagnostics and Troubleshooting 7 8 Notes AB Spares ...
Page 117: ...Chapter 8 Application Examples 8 10 Notes AB Spares ...
Page 123: ...Appendix A Specifications A 6 Notes AB Spares ...
Page 125: ...Appendix B RTD Standards B 2 Notes AB Spares ...
