National Instruments NI 9871 - Specifications

Figure 4. 4-Wire Full-Duplex Multidrop Network
Using Terminating Resistors
MASTER
Slave 1
120 Ω
Slave 2 Slave n
120 Ω
Tx
Tx
Rx
Tx
Rx
Tx
Rx
Rx
120 Ω
120 Ω
Figure 5. 2-Wire Multidrop Network Using Terminating Resistors
MASTER
Slave 1
120 Ω
Slave 2 Slave n
120 Ω
Tx
Tx
Rx
Tx
Rx
Tx
Rx
Rx
The driver directly supports 4-wire full-duplex operation on peer-
to-peer RS-485 networks. Multidrop RS-485 networks require
additional software development.
RS485 terminators are available at ni.com/serial.
NI 9871 Getting Started Guide | © National Instruments | 13