Meggitt vibro-meter SpeedSys300 ODS301, User Manual, Page: 46 / 170

USER MANUAL Document reference MAODS301/E
SpeedSys300 ODS301 overspeed detection system Edition 4 - May 2022
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Installation considerations
INSTALLATION OF A SPEEDSYS300 ODS301
3.2.5.1 1oo2 voting
With a 1oo2 voting logic structure, two devices/relays are connected in series such that a
1oo2 signal is given if one of the devices switches its relay (see
Figure 3-2 ).
Accordingly, to obtain a 1oo2 voting logic structure, the safety relays from two SpeedSys300
ODS301 modules should be connected (hardwired) together in series, as shown in
Figure 3-2 .
Module #2
Relay B
Figure 3-2: 1oo2 voting – relay connections
1oo2
Module #1
Relay A