Allen-Bradley 1732ES-IB12XOB4, User Manual, Page: 20 / 176

20 Rockwell Automation Publication 1791ES-UM001G-EN-P - November 2016
Chapter 1 Safety Function Operation
Safety Input Fault Recovery
If an error is detected, the safety input data remains in the off state. Follow this
procedure to activate the safety input data.
1. Remove the cause of the error.
2. Place the safety input (or safety inputs) into the safety state.
The safety input status turns on (fault cleared) after the input-error
latch time has elapsed. The I/O indicator (red) turns off. The input data
can now be controlled.
Input Delays
On-delay – An input signal is treated as logic 0 during the on-delay time
(0…126 ms, in increments of 6 ms) after the rising edge of the input contact.
The input only turns on if the input contact remains on after the on-delay time
has elapsed. This delay helps prevent rapid changes of the input data due to
contact bounce.
Figure 8 - On-delay
Off-delay
– An input signal is treated as logic 1 during the off-delay time
(0…126 ms, in increments of 6 ms) after the falling edge of the input contact.
The input only turns off if the input contact remains off after the off delay time
has elapsed. This delay helps prevent rapid changes of the input data due to
contact bounce.
Figure 9 - Off-delay
44094
ON
OFF
ON
OFF
Remote I/O
Data Safety
Input
Input Signal
ON-delay
On-delay
ON
OFF
ON
OFF
Input Signal
Remote I/O
Data Safety
Input
OFF
ON
OFF Safety Input
Input Signal
OFF-delay
Remote I/O Data Remote I/O Data
Safety Input
Off-delay
Input Signal
ON
OFF
ON
OFF