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Rockwell Automation Publication 1715-UM001J-EN-P - December 2020
Appendix B 1715-IB16D Digital Input Module Diagnostics
Figure 79 - Open Switch/Off Condition
If 5.1V is present, we know that the switch is in the off position. We can enter a
range into the threshold that lets 5.1V to be an off condition. We used 3.0 …6.5V
as the range. So, if the voltage drops below 3.0V, it is considered a wire off. If it
goes above 6.5V, it is considered indeterminate.
Shield
(if used)
Terminal
Blocks
OV
20
Ω
100
Ω
50 mA
4.99k
Ω
Termination
Assembly
+24V DC
R1
R2
45678
User-calculated Voltage
5.1 K
SW1
3.9 k
15 k
45680