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Rockwell Automation Publication 1734-UM013C-EN-P - August 2010
Chapter 2
Safety Functions
Safety Outputs
Read this section for information about safety outputs.
Safety Output with Test Pulse
When the safety output is on, the safety output can be configured to pulse test
the safety output channel.
By using this function, short-circuits between output signal lines and the power
supply (positive side) and short-circuits between output signal lines can be
detected. If an error is detected, the safety output data and individual safety
output status turn off.
Figure 12 - Test Pulse in a Cycle
For the 1734-OB8S module, the pulse width (X) is typically 475 μs; the pulse
period (Y) is typically 575 ms.
IMPORTANT
To prevent the test pulse from causing the connected device to
malfunction, pay careful attention to the input response time of
the output device.
44096
X
Y
OUT
On
Off