Rockwell Automation Publication 1791ES-UM001G-EN-P - November 2016 23
Safety Function Operation Chapter 1
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 test pulsed, as shown in 
Table 4
 and Figure 11.
By using this function, the following can be detected:
• Short circuits between sourcing output signal lines and the power supply 
(positive side)
• Short circuits between sinking output signal lines and the power supply 
(negative side)
• Short circuits between output signal lines of the same polarity (from 
sourcing output to sourcing output or from sinking output to sinking 
output)
If an error is detected, the safety output data and individual-safety output 
status turns off.
Figure 11 -  Test Pulse in a Cycle
 
ATTENTION: Serious injury can occur due to the breakdown of safety 
outputs. Do not connect loads beyond the rated value to the safety outputs.
Table 4 -  Safety Output Test Pulse
Pulse Width Period
700 μs 600 ms
IMPORTANT To prevent the test pulse from causing the connected device to 
malfunction, pay careful attention to the input response time of the 
device.
OUT
On
Off
Typ ic al 
700 μs
Typ ic al 
600 ms