NI 9871 Operating Instructions
12
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RS485 Transceiver Control
Refer to Table 3 for a listing of TX and RX enable conditions for
the different RS485 transceiver control modes.
NI 9871 Hardware Overview
The NI 9871 has four independent RS485/RS422 ports that are
isolated from the other modules in the system. Each port is fully
compatible with the ANSI/EIA/TIA-485 standard.
Table 3.
Transceiver Control Pin Conditions
Enable
4-Wire
2-Wire
DTR/Echo
DTR/No Echo
Auto
TX
On
DTR
DTR
TX
RX
On
On
DTR#
TX#
