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Theory of Operation
Chapter 3
SCXI-1160 User Manual
3-8
© National Instruments Corporation
advisable to avoid energizing the relay coils that will not be changing states. To achieve this,
write zeros in the Data Register locations belonging to the relays that do not need to change
states. Refer to Chapter 4, Register Descriptions, and Chapter 5, Programming, for further
details.
The relays are break-before-make, as long as you do not exceed the specified relay operation
speed. In addition, each relay is fully isolated from the other relays and from earth ground, with
a working common-mode voltage of 250 Vrms and a breakdown of 1,500 Vrms.
Note: It is important to notice that this module has no access to the analog backplane; this
protects the backplane from faults when high voltages are available on the relay contacts.