Chapter 5
Channel Configuration, Data, and Status
5–12
Table 5.L
Channel Data Word Resolution for 500
W
, 1000
W
, and 3000
W
Resistance Inputs
Data Format (Bits 4 and 5)
Resistance Input Type
Engineering Units x 1
Engineering Units x 10
Scaled–for–PID
Proportional Counts
(Default)
Ohms
Ohms
Ohms
Ohms
500
W
0.1
Ω
/ step
1
Ω
/ step
0.0305
Ω
/ step
0.0076
Ω
/ step
1000
W
0.1
Ω
/ step
1
Ω
/ step
0.0610
Ω
/ step
0.0153
Ω
/ step
3000
W
0.1
Ω
/ step
1
Ω
/ step
0.1831
Ω
/ step
0.0458
Ω
/ step
Broken Input Selection (Bits 6 and 7)
Table 5.M shows the descriptions for bits 6 and 7. The broken input bit field
lets you define the state of the channel data word when an open–circuit or
short–circuit condition is detected for that channel.
An open–circuit condition occurs when the RTD or potentiometer or its
extension wire is physically separated or opened. This can happen if the wire
is cut or disconnected from the terminal block.
The short–circuit condition applies only to RTD input types. This can
happen if the RTD or its signal wires are shorted together for any reason.
The short–circuit condition does not apply to resistance ranges since they
start at 0 ohms, which can be a short–circuit condition.
Table 5.M
Bit Descriptions for Broken Input Selection
Binary
Value
Select
Description
00
zero
force the channel data word to 0 during an open–circuit condition or
short–circuit condition.
01
upscale
force the channel data word value to its full scale value during an
open–circuit or short–circuit condition. The full scale value is
determined by the input type, data format, and scaling selected.
10
downscale
force the channel data word value to its low scale value during an
open–circuit or short–circuit condition. The low scale value is
determined by the input type, data format, and scaling selected.
ÉÉÉ
ÉÉÉ
11
ÉÉÉÉÉ
ÉÉÉÉÉ
not used
Temperature Units Selection (Bit 8)
Table 5.N shows the description for bit 8. The temperature units bit lets you
select temperature engineering units in
°
C or
°
F for RTD input types. This
bit field is only active for RTD input types. It is ignored when the resistance
input type is selected.
AB Spares
Содержание SLC 500 1746-NR4
Страница 1: ...User Manual SLC 500t RTD Resistance Input Module Cat No 1746 NR4 Allen Bradley AB Spares ...
Страница 15: ...Preface P 8 Notes AB Spares ...
Страница 37: ...Chapter 2 Quick Start 2 12 Notes AB Spares ...
Страница 63: ...Chapter 4 Preliminary Operating Considerations 4 12 Notes AB Spares ...
Страница 87: ...Chapter 5 Channel Configuration Data and Status 5 24 Notes AB Spares ...
Страница 107: ...Chapter 7 Module Diagnostics and Troubleshooting 7 8 Notes AB Spares ...
Страница 117: ...Chapter 8 Application Examples 8 10 Notes AB Spares ...
Страница 123: ...Appendix A Specifications A 6 Notes AB Spares ...
Страница 125: ...Appendix B RTD Standards B 2 Notes AB Spares ...