ELOE174ZKE002
3
1.0
Introduction
RS-422 (V.11) is a duplex interface for two devices´ communication. The
symmetric signals are transmitted via the twisted pair and they are immune to the
interference. Maximum range is 1200m which can be increased using repeaters.
1.1
Use of the converter
The fibre optic cable is immune to electromagnetic interference and atmospheric
electricity influences, it provides maximum DTE protection and high
communication reliability. The distance between devices is not more than 2km so
using multimode fibres is economically convenient in automation.
2.0
Operation principles
The converter transfers Tx signal of the RS-422 interface to the transmitting optic
fiber and copies it from the receiving optic fiber to Rx of the RS-422 interface.
Maximum data rate limit is 115.2 kbps. LED diodes indicate the transmitted and
received signal.
3.0
Installation
This part describes the ELO E174 converter installation principles.
3.1
Optic link connection
ST 400 connectors are used to connect the fiber optic cable. To connect two
converters, the TRANSMIT connector of the local converter has to be connected to
the RECEIVE connector of the remote converter and the RECEIVE of the local
converter has to be connected to the TRANSMIT connector of the remote one. The
cable has to be multimode 50/125 or 62.5/125μm and it should not be longer than
2 km are recommended.
3.2
RS-422 interface connection
RS-422 interface connector is DB9F (female), signals assignment to the contacts
(see the Fig.). If the OUT +5V and IN +8V signals are not used the DTE can be
connected to the converter via the cable up to 1200m long or the tolerable supply
voltage decrease limits the cable length.
