National Instruments NI 9871 Getting Started Guide

You must connect an external power supply to the NI 9871. This
power supply provides the power for the RS485/RS422
transceivers on the module. You can use the included female
four-position pigtail to connect to an external voltage source.
Figure 1 lists the connections between an external voltage source
(of +8 V to +28 V) and the NI 9871.
Caution To ensure the specified EMC performance,
do not connect the power input to a DC mains supply
or to any supply requiring a connecting cable longer
than 30 m (100 ft). A DC mains supply is a local DC
electricity supply network in the infrastructure of a
certain site or building.
NI 9871 Getting Started Guide | © National Instruments | 9

National Instruments NI 9871 Specifications

General

Brand	National Instruments
Model	NI 9871
Category	Control Unit
Language	English