Internal Power Options; Using External Power - National Instruments FlexRIO NI 6581B Getting Started Manual

External Power
Connector
Internal Selectable
Power Supply

Internal Power Options

You can use one of the internal power options shown in the following table to power one or
both DDC connectors.
Voltage
3.3 V
2.5 V
1.8 V

Using External Power

Use the power connector to externally power the NI 6581/6581B. If you do not want to use the
predefined internal voltages, you can select external power in software for one or both DDC
connectors. Complete the following steps to wire a variable power supply to the power
connector with 20–26 AWG wires.
1. Using wire strippers, carefully remove 11 mm (0.43 in.) of insulation from the signal
wires.
2. Wire the voltage output of the power supply to the +VA terminal and/or +VB terminal,
depending which DDC connector(s) you want to power. Press a small flathead
screwdriver on the spring terminal lever to open the terminal, and insert the wire into the
spring terminal opening.
Figure 5. NI 6581/6581B Power Circuitry Diagram
DDCA
DDCB
GND
+ VA
+ VB
3.3 V
2.5 V
1.8 V
Table 5. Internal Power Supply Voltage Settings
0
1
2
VCC_AUXA
VCC_AUXB
VCC_AUXB
Setting in LabVIEW
NI 6581/6581B Getting Started Guide | © National Instruments | 9
VCC_AUXA