Meggitt vibro-meter SpeedSys300 ODS301, User Manual

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Document reference MAODS301/E USER MANUAL
Edition 4 - May 2022 SpeedSys300 ODS301 overspeed detection system
3 - 11
Installation considerations
INSTALLATION OF A SPEEDSYS300 ODS301
3.2.5.2 2oo2 voting
With a 2oo2 voting logic structure, two devices/relays are connected in parallel such that a
2oo2 signal is given if both devices switch their relays (see
Figure 3-4 ).
Accordingly, to obtain a 2oo2 voting logic structure, the safety relays from two SpeedSys300
ODS301 modules should be connected (hardwired) together in parallel, as shown in
Figure 3-4 .
Figure 3-4: 2oo2 voting – relay connections
2oo2
Module #1
Relay A
Module #2
Relay B