67
W&T
Subject to error and alteration
USB Interfaces
USB <> RS422/RS485 Interface, #36201
The 36201 Interface allows galvanically isolated, bi-directional
connection of RS422 and RS485 devices to computers having
an USB port.
The Interface supports one data and one handshake line each
in both directions and provides galvanic isolation between the
USB and the RS422/RS485 side. The converter is contained in a
plastic housing for mounting to standardized rails according
to EN 50022-35.
Power supply
The supply voltage for the Interface is provided by means of an
integrated switching regulator. This regulator has a variable
input voltage range and allows the Interface to be supplied by
any DC or AC voltage between 12 and 24 volts. The supply
voltage line is polarity reverse protected and is connected using
the plug-in screw terminal provided.
It is unfortunately not possible to supply the Interface from the
USB, since a voltage of at least 12 V is required.
Galvanic isolation and ESD protection
Both ports on the Interface are galvanically isolated to 1kV both
from each other and from the supply voltage. Galvanic
isolation of the signals is accomplished using fast opto-
couplers; the driver and receiver chips on the USB and RS422/
RS485 side are supplied with power by a galvanically isolated
DC/DC converter.
All RS422/RS485 signal lines are protected against static
discharge up to a voltage of 15kV according to IEC 801-2,
Level 4.
