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 connected. If
there are more serials, more device linescan be served.
Most Dixell controllerdevices are equipped with an RS485 serialoutput and can be connected without the
need for 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 DixellXJ485 converter.It converts the controller outputfrom "TTL" (five wires) to "485" (two
wires). If you need to use the TTL / 485 converter, please payattention in:
•Keep the TTL cable away from any source of electromagnetic disturbance
•Connect each XJ485 module to the instrumentwith the TTL cable supplied with the module itself
•Mark the polarityof output 485 which must be respected when connecting the instruments to the
network
Below is a list of operating tipsto obtain the best result in terms of instrument net work reliability, RS485
serial connection:
•The serial line cable can be of the two-wire type plus the shield, with a minimumsection of 0.5mm2
(eg BELDEN 8772). This cable isrecommended for its technical characteristics and formaintaining
the quality of the electrical signal;
•The serial line cable must reachall the instrumentstations: check the plant layout and the various
distances thatthe cable will have to travel;
•The serial line cable can reach a maximum length of 1 km
•Respect the polaritiesindicated on the instrument withthose ofthe cablesleading to the serial
•Keep the serial cable away from power cables and any possible source of electromagnetic
disturbance
•Do not connectthe shield of the serial cable to the earth of the electrical system
•Do not connect the “Gnd” terminal.
•Drawa map of the installation you are performing: itwill beusefulboth in case of problems and in
case of future changes; the serial line must reach all the stations where the instruments must be
controlled.