VISION
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PAN
Pag. 18
USER AND MAINTENANCE MANUAL
Rev. 01-19
CONNECTION TO RS-485 FOR TELENET OR MODBUS-RTU
1) Example of connection between the console and the Modbus line:
It is recommended to connect a resistance equal to 120
between A and B at the
beginning and end of the line in case of communication problems.
For a correct functioning the MASTER has to have a RS485 polarized.
Connect the earth to the GND
terminal of M3 in the console
(functional earth). This connection
helps to limit the effects of the
electromagnetic noise on the
control system.
The ground connection must be
made in a manner consistent with
applicable regulations.
Connect the terminal (A) of M3 in
the console to signal A of the
Modbus line and the terminal (B)
of M3 in the console to signal B of
the Modbus line. Connect the
braid of the shielded cable to the
terminal (GND) of M3 in the
console.
Use twisted cable suitable for the
transmission of RS485 signals with
minimum section of 0.5mm
2
(e.g.
Belden 8762 cable).
Avoid coupling with power cables.
3.7
