Power Switch; Power Source - National Instruments R Series User Manual

Power Switch

Use the power switch to power the NI USB-7846R OEM device on and off. The following
figure shows the pins on the power switch and power circuitry.
100 kΩ
The following table lists the pin locations and signal descriptions.
Pin Signal
1 VDC In
2 VDC Out
3 100 kΩ to
Ground
+5 V Power Source
Use the +5 V terminals on the I/O connector supply +5 V referenced to DGND to power
external circuitry.
Caution
any other voltage source on the NI USB-7846R OEM device or any other device.
12 | ni.com | NI USB-7846R OEM User Manual
Figure 11. Power Switch (Shown in the On Position)
100 kΩ
VDC Out
to Ground
3 2 1
Switch
SW2
NC NC
Power to
Device
100 kΩ
Table 4. Power Switch Pin Descriptions
Connects to VDC through a non-user replaceable fuse (reference
designator F1). The VDC is the voltage provided by the power supply
through pin 2 of the power connector (reference designator J8) and
must be 9 V to 30 V, 20 W.
Provides power to the circuitry on the NI USB-7846R OEM device.
When the switch is in the on position, the VDC power supply from pin
1 is routed to pin 2.
Connects pin 2 to ground through a 100 kΩ resistor when the switch is
in the off position.
Never connect the +5 V power terminals to analog or digital ground or
VDC In
Connector
J8
1 2
SW2 J8
F1
1
2
2
Power
3
Connector
1
Description