©
National Instruments Corporation
29
NI Switches Getting Started Guide
Figure 25.
Installing a Terminal Block
Derating Modules That Share the HVAB
As a safety precaution, modules that share a common HVAB must be
derated to their lowest common voltage rating, even if they do not connect
signals to the backplane. Refer to Figure 2 to determine if your switch has
an HVAB connector. The following examples demonstrate how to derate
your modules.
Example 1
SCXI-1000 chassis
SCXI-1359 2-slot backplane adapter behind slots 3 and 4
SCXI-1127 (250 V, CAT II) in slot 4
SCXI-1129 (150 V, CAT I) in slot 3
Both modules share the HVAB and the SCXI-1127 must not exceed the
rating of the SCXI-1129 (150 V, CAT I).
1
Switch Module
2
Thumbscrews
3
Terminal Block
4
Signal Wires
5
Chassis
1
2
3
5
4
