Emerson Rosemount OPM3000, Инструкция по эксплуатации

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Instruction Manual Rev B
46
RS485: Pin out
Use RS485 to create a multi-drop network containing up to 32 devices.
Note: port #1is set to RS485

Note that the ports are not isolated. If controller is
used with a non-isolated external device, avoid
potential voltage that exceeds +/- 10V. To avoid
damaging the system, all non-isolating device ports
should relate to the same ground signal.

Use shielded, twisted pair cables.

Minimize the stub (drop) length leading from each device to the bus.

Ideally, the main cable should be run in and out of the network device.

Do not cross positive (A) and negative (B) signals. Positive terminals must be wired to positive and negative
terminals to negative.