Chapter 6
Ladder Programming Examples
6–10
Figure 6.9 shows how you could monitor the open– and short–circuit error
bits of each channel and set an alarm in the processor if one of the RTDs or
resistance–input devices (such as a potentiometer) opens or shorts. An
open–circuit error can occur if the RTD or resistance–input device breaks or
one of the RTD or resistance–input device wires get cut or disconnected from
the terminal block. A short–circuit condition applies only to RTD input.
Figure 6.9
Programming to Monitor Channel Status
] [
COPY FILE
Source
#N10:0
Dest
#O:3.0
Length
4
First Pass Bit
S:1
15
Rung 2:0
COP
Initialize RTD module.
11
Rung 2:1
Channel 0
Status
] [
I:3.4
] [
I:3.4
13
( )
O:2.0
0
Channel 0
Open or Short
Channel 0
Alarm
11
Rung 2:2
Channel 1
Status
I:3.5
13
( )
O:2.0
1
Channel 1
Open or Short
Channel 1
Alarm
I:3.5
] [
] [
11
Rung 2:3
Channel 2
Status
I:3.6
I:3.6
13
( )
O:2.0
2
Channel 2
Open or Short
Channel 2
Alarm
] [
] [
11
Rung 2:4
Channel 3
Status
I:3.7
] [
I:3.7
13
( )
O:2.0
3
Channel 3
Open or Short
Channel 3
Alarm
] [
Rung 2:5
END
Data Table
address 15 data 0 address 15 data 0
N10:0 0000 1001 0001 0001 N10:3 0000 1001 0001 0001
N10:1 0000 1001 0001 0001
N10:2 0000 1001 0001 0001
Monitoring Channel Status
Bits
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 ...
