Rs-485 Half-Duplex Wiring Example - Campbell SDM-SIO1A Instruction Manual

SDM-SIO1A Serial Input/Output Module

6.2.1.3 RS-485 Half-Duplex Wiring Example

NOTE
12
This shows how to connect a single device, but RS-485 half-duplex networks
are the most common multi-drop configuration. If wiring for multiple devices,
make the three wire connections in parallel, similar to that shown in the full-
duplex multi-drop example.
As with all RS-485 configurations, the use of termination resistors
is optional. They tend not to be required with shorter cable runs
and with modern slew-rate-limited driver technology (as used in
the SDM-SIO1A).