National Instruments NI 6520, User Manual, Page: 16 / 23

NI 6520/6521 User Guide 16 ni.com
(NI PXI-6521 Only) The maximum power rating for the NI PXI-6521 relays
is 60 W or 60 VA, with a maximum current of 2 A for all channels from 0 to
55 °C, external PXI chassis ambient.
(NI PCI-6521 Only) The maximum power rating for the NI PCI-6521 relays is
60 W or 60 VA. Figure 9 demonstrates the maximum current ratings for the
NI PCI-6521 relays from 0 to 55 °C.
Figure 9. NI PCI-6521 Relay Power Ratings
Power-On and Power-Off Conditions
The relays on the NI 6520/6521 have the default statuses of deenergized
(control bit is low) in both power-on and power-off states. For more
information on default states of the NI 6520/6521 relays, refer to the
Programmable Power-Up States section and the Non-Latching Relays
section.
Relay Signal Connection Example
To connect to the NI 6520/6521 signals for Form C relays, connect NC,
NO, and COM, as shown in Figure 10.
Figure 10. Relay Signal Connection Example for Form C Relays
55 50 45 40 35 30 25 20 15 10 5 0
2.0
1.6
1.2
0.4
0.2
0
Ambient Temperature (
°
C)
Maxim
um Current (Amps) 0.6
0.8
1.0
1.4
1.8
2.2
External PC Ambient—All Channels
Load B Load A
P1. X COM
P1. X NC
P1. X NO
Power