72 Rockwell Automation Publication 5094-UM001E-EN-P - April 2020
Chapter 5 Safety I/O Module Features
Figure 8 - 5094-IB16S and 5094-IB16SXT Test Pulse in a Cycle
On the 5094-IB16S and 5094-IB16SXT modules, the pulse width (X) is less 
than 600 μs; the pulse period (Y) is less than 100 ms.
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 can be detected. However, a short circuit between two input channels 
cannot be detected if these two channels correspond to the same Test Output. 
For example, Test Output 0 associates to Safety Input 0 and 8. If these two 
channels short circuit, it cannot be detected.
Figure 9 - Short Circuit Between Input Signal Lines