CIAT AQUACIATPOWER ILD-HE Series, Инструкция по эксплуатации

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4.8 RS485 wiring (best practice)
For RS485 ports, one of the following cables can be used:
■ two twisted pairs + a shield (RECOMMENDED)
■ three wires + a shield
Note that “+” and “-” are communication signals and they are
from the same twisted pair.
The signal ground could be a single wire or a twisted pair and it
should be connected to the “C” pin of J10 (Modbus RTU) or J7
(Proprietary Protocol). This wire is required so that all nodes on
the bus share a common ground reference connection.
If a shield is used, then the shield cable should be properly
terminated and connected as short as possible at ONLY one
end to the chassis ground (4.3-inch controllers).
4.8.1 RS485 wiring: 4.3-inch controller
The following diagrams illustrate possible RS485 wiring
schemes for 4.3-inch controllers.
The first wiring scheme is the best option (RECOMMENDED),
but the second or the third wiring can also be used.
4 - HARDWARE
No.1 RS485 wiring diagram (RECOMMENDED)
No. 2 RS485 wiring diagram (CORRECT)
No. 3 RS485 wiring diagram (CORRECT)
No. 4 RS485 wiring diagram (INCORRECT - Do not use!)
No. 5 RS485 wiring diagram (INCORRECT - Do not use!)
4.8.2 RS485: Daisy chain configuration
The following illustration shows proper 3-wire cable with
a shield in a daisy chain configuration.
B C
D
Legend
B
Shield
C
Keep shield continued
D
Connect shield to earth ground only at one point
End of Line Resistor: Termination is only needed when running
at bus at very high speed over long distances.
The speed of the bus and the cable distance determine
whether termination is needed. It is meant to balance the bus
to minimize the ringing that may be caused by fast signals and
the inductance of the cabling.
At 9600 baud, termination will have little or no effect on the bus.
AQUACIAT POWER EN-10