Emerson XWEB300D, Инструкции по установке и эксплуатации

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1592028040 XWEB300D_500D_PRO STP GB r1.0 25.11.2020.doc XWEB PRO 10/20
5.2 CONTROLLERS
XWEB has at least one RS485 serial port, on which the line of the controller devices can be c onnected. If
there are more serials, more device lines can be served.
Most Dixell controller devices are equipped with an RS485 serial output and can be connected wit hout t he
need f or any additional module or connection cable. To make sure of this possibility, check the
characteristics of the controller in its manual.
Some Dixell devices however, may not be direct, but it can be obtained via the small external Dixell
XJRS485 or Dixell XJ485 converter. It converts the controller output from "TTL" (f iv e wires) t o " 485" (t wo
wires). If you need to use the TTL / 485 converter, please pay attention in:
•
Keep the TTL cable away f rom any source of electromagnetic disturbance
•
Connect each XJ485 module to the instrument with the TTL cable supplied with the module itself
•
Mark the polarity of output 485 which must be respected when connecting t he inst rument s t o t he
network
Below is a list of operating tips to obtain the best result in terms of instrument net work reliability , RS 485
serial connection:
•
The serial line cable can be of the two-wire type plus the shield, with a minimum section of 0. 5mm2
(eg BELDEN 8772). This cable is recommended for its technical characteristics and for maintaining
the quality of the electrical signal;
•
The serial line cable must reach all the instrument stations: check the plant layout and t he various
distances that the cable will have to travel;
•
The serial line cable can reach a maximum length of 1 km
•
Respect the polarities indicated on the instrument with those of the cables leading to the serial
•
Keep the serial cable away f rom power cables and any possible source of electromagnetic
disturbance
•
Do not connect the shield of the serial cable to the earth of the electrical system
•
Do
not connect the “Gnd” terminal.
•
Draw a map of the installation you are performing: it will be useful both in case of pro blems and in
case of future changes; the serial line must reach all the stations where t he ins trument s must be
controlled.