Rockwell Automation Publication 35-UM001A-EN-P - May 2022
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Chapter 6 Safety Functions
On to Off Delay
Off-delay—An input signal is treated as Logic 1 during the off-delay time
(0…65,535 ms, in increments of 1 ms) after the falling edge of the input contact.
The input turns off only if the input contact remains off after the off delay time
has elapsed. This setting helps prevent rapid changes of the input data due to
contact bounce.
Figure 62 - Off-delay
Using a Test Output with a Safety Input
A test output can be used in combination with a safety input for short circuit,
cross-channel, and open-circuit fault detection. Configure the test output as a
pulse test source and associate it to a specific safety input.
Figure 63 - Test Output Wiring Example
Figure 64 - Test Pulse in a Cycle
The pulse width (X) is typically 500 μs. The pulse period (Y) is typically 300 ms.
The relation between pulse period and width is fixed.
When the external input contact is closed, a test pulse is output from the test
output terminal to diagnose the field wiring and input circuitry. By using this
function, short-circuits between inputs and 24V power, and between input
signal lines and open circuits can be detected. See
.
Safety Input
Network Data
Off-delay
Input Signal
ON
OFF
ON
OFF
1
4
5
2
3
Safety Input
1 - Test Output 1
2 - Safety Input 1
3 - Input Common
4 - Safety Input 0
5 - Test Output 0
Socket View
X
OUT
Y
On
Off
