Iron logic Z-397 User Manual

Z-397 USB/RS-485/RS-422 www.ironlogic.me
Converter
Z-397 USB/RS-485/RS-422
User Manual

1. GENERAL INFORMATION

Converter Z-397 USB/RS-485/RS-422, is intended to
connect the devices with interfaces RS-422 and RS-
485 to a personal computer, using a USB interface.
Product Features:
1) A galvanic separation unit of 422/485 interface up to
1000 V is provided to exclude the influence of pulse
interference exerted by a PC power supply unit on
devices connected to the PS and vice versa;
2) Connection to the PC and power supply via the USB
interface;
3) Operation via a virtual COM-port;
4) Automatic identification of the speed of information exchange through the USB interface;
5) Automatic identification of transmittance direction when working in a half-duplex mode: in the
initial condition the converter is waiting for data both from the connection channel and from the PC. In
case of simultaneous transmittance, the PC will prevail. Transition from the transmittance status to
the reception condition on any speed does not increase 1 microsecond after transmittance of the last
stop-bit in the data package. Controlling the transmittance direction via RTS is ignored and does not
influence upon operation of the converter;
6) Existence of mode switchers: the converter allows you to easily adjust the operation mode using
four switchers.
Switchers 1 and 2 serve to switch between RS-422 interfaces (both in OFF position) and RS-485
(both in ON position).
The switcher 3 serves to switch the modes of FULL DUPLEX (simultaneous transmittance and
reception, position OFF) and HALF DUPLEX (half duplex mode, ON position).
Attention! The FULL DUPLEX mode can work only in case of RS-422. When using RS-485, this
switch must be in ON position.
The switch 4 in ON position connects the load resistor to AB lines.
7) The existence of a control channel: the control channel may be connected to COM-port of the
computer, and using any terminal programme you can monitor the exchange protocol.

2. CONNECTION

CONNECTION USING RS-422 AND RS-485 INTERFACES
RS-422 and RS-485 interfaces are the further development of the widely spread serial interface RS-
232C.

CONNECTION USING RS-422

Although the RS-422 interface is used to connect several devices, actually it is used for point-point
connection.
The RS-422 interface supports maximal transmittance speed of 10 Mbit/s with the connection line's
length of up to 15 m and 90 Kbit/s with the connection line's length of up to 1200 m.
The above is related to a symmetrical connection using a twisted-pair cable. To implement this
connection, two twisted-pair cables are required.
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