Rockwell Automation 440R-D22R2, User Manual

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Rockwell Automation Publication 440R-UM013F-EN-P - July 2021 61
Chapter 11 Troubleshooting
Figure 65 - DI, DIS, and SI Safety Relay Pulse Test Waveforms
Effect of OSSD Test Pulses
GSR safety relays cannot detect short circuits of OSSD outputs. The PWR/Fault
status indicator of your GSR safety relay remains steady green. The device with
the OSSD outputs must detect short circuits of its own OSSD outputs. When
detected, the device must shut off both OSSD outputs and go to a faulted state.
A status indicator must inform you that the OSSD is faulted. See
Devices with
OSSD Output on page 20 for more information.
Detect Off Pulses
When configured for monitored manual (or manual) reset, the GSR safety
relay detects off pulses as described in
Table 15 .
Test pulses on OSSD outputs are less than 1 ms; therefore the GSR safety relay
ignores the test pulses.
Capacitance Effect
Capacitance leakage of the input wiring to ground causes a deformation of the
leading edge of the pulses.
Figure 66 on page 62 shows the deformation with
1 μF on each signal to ground. With this high capacitance, the CI safety relay
still operates.
Capacitance from Ch1 to Ch2 looks the same as Ch1 to ground and Ch2 ground.
Table 15 - Off Pulses
Time Description
Off time ≥25 ms
GSR safety relays always detect when the input device turns OFF. GSR safety relays also
detect that the input device has turned back ON.
7 ms < Off time < 25 ms
When the off pulse is between 7…25 ms, GSR safety relays turn their output OFF, but the
input does not turn back ON. The input must be cycled again.
Off time <7 ms GSR safety relays cannot detect inputs that turn OFF for 7 ms or less.
Terminal S11
Terminal S21