Allen-Bradley Guardmaster, User Manual

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70 Rockwell Automation Publication 440R-UM013E-EN-P - March 2017
Chapter 11 Troubleshooting
Examine Pulse Test Waveforms
If you have an oscilloscope, you can examine the pulse tests. The test pulses are
used to check for short-circuit conditions; the test pulses are not used to turn
the inputs ON and OFF. If they are clean and square, then they are OK.
The test pulses are generated on terminals S11 and S21. The waveforms, which
are shown in Figure 64 and Figure 65 , must always be present on their
respective relays; the test pulses cannot be turned off or adjusted.
Figure 64 - CI Safety Relay Pulse Test Waveforms
Figure 65 - DI, DIS, and SI Safety Relay Pulse Test Waveforms
Effect of OSSD Test Pulses
GSR relays cannot detect short circuits of OSSD device outputs. The PWR/
Fault status indicator of your GSR relay remains solid green. The device with
the OSSD outputs must detect short circuits of its own OSSD outputs. When