Chapter 5
Channel Configuration, Data, and Status
5–14
Table 5.P
Bit Descriptions for Channel Enable Selection
Binary
Value
Select
If you want to
0
channel disable
disable a channel. Disabling a channel causes the channel data
word and the channel status word to be cleared.
1
channel enable
enable a channel.
Excitation Current Selection (Bit 12)
Table 5.Q gives the description for bit 12. Use this bit to select the
magnitude of the excitation current for each enabled channel. Choose from
either 2.0 mA or 0.5 mA. This bit field is active for all inputs. A lower
current reduces the error due to RTD self heating, but provides a lower
signal–to–noise ratio. Refer to RTD vendor for recommendations. See page
ii for general information.
Table 5.Q
Bit Description for Excitation Current Selection
Binary
Value
Select
Description
0
2.0 mA
set the excitation current to 2.0 mA.
1
0.5 mA
set the excitation current to 0.5 mA.
Scaling Select (Bits 13–14)
If you selected proportional counts as the format for your input data, you can
enter a scaling range that ensures your data is scaled within a range
appropriate for your use. You can use words 4 and 5 to define one range and
words 6 and 7 to define a second range. Table 5.R gives the descriptions for
bits 13 and 14.
AB Spares
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 ...
