National Instruments RS485 - Manual (Page 9)

© National Instruments Corp. 9 NI 9871 Operating Instructions
Figure 2 shows the method of power connection to the NI 9871
module. Attach an isolated power supply to the V
sup
and COM
terminals using the included pigtail.
Figure 2. Powering the NI 9871 from an Isolated Power Source
Figure 3 shows how to use the optional y-adapter (available at
ni.com/serial ) to connect power to more than one module
using the same power source. One y-adapter is needed for each
Red (+)
Black (–)
NI P/N 198159-XX:
Female Microfit
Pigtail
V+
V–
Any 8 - 28 V
Isolated
Power Supply