Elo TouchSystems E06G Operation Manual

RS-232/RS-485 Converter with HW and Automatic

Control without Galvanic Isolation of the Interface

ELO E06G

Operation manual

ELOE06GZKE001

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1.0 Introduction...........................................................................2

1.1 Use of the converter...............................................................2

2.0 Operation principles...............................................................3

3.0 Installation.............................................................................3

3.1 Converter connection to RS-232 Interface.............................3

3.2 RS-485 link connection..........................................................4

3.3 Converter setting....................................................................5

3.4 Power Supply Connection......................................................5

4.0 Specifications.........................................................................6

4.1 Electrical parameters.............................................................6

4.2 Other......................................................................................6

5.0 Testing...................................................................................7

6.0 Troubleshooting.....................................................................7

7.0 Ordering information............................................................7

1.0 Introduction

RS-232 interface is designed for two terminal equipments connection (DTE).
RS-232 interface range is limited to 15m distance. RS-485 interface signals
transmission enables to increase communication range, transmission interference
immunity and communication partners´ number.

1.1 Use of the converter

The converter increases transmission immunity against electrical disturbance but
not against atmospheric electricity influences! To lead the cable outside

buildings, it is necessary to provide additional over-voltage protection on the input
points. The converter allows transmission rate up to 115200 bps. This maximum
attainable rate decreases due to the line length and/or its impedance growth.
Recommended maximum line length is 1200 m at the rate of 9600 bps.

ELOE06GZKE001

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2.0 Operation principles

RS-485 interface is used to two-way simultaneous communication in one pair of
conductors. For this reason, the transmission has to be half-duplex that means
switching off RS-485 transmitter when receiving to allow transmitting to other
communication partners and switching on during its own transmitting only. There
are two methods how to operate the transmitter:

1) The transmitter is controlled from DTE by signal RTS or its invert polarity.

2) DTE does not use RTS (this interface does not dispose this signal or SW does

not use it) and the converter has to interpret its signal TxD automatically. At
the TxD changing moment from idle state (from the negative to positive
polarity), the converter activates the link transmitter automatically. The
transmitter is switched off after the certain time τ of RTS switching off or
TxD return to the neutral polarity. Time interval length τ has to be dependent
on applied transmission rate because in the automatic mode there it is
necessary to keep the transmitter active for the period equal to one byte

transmission time.
In the automatic mode, every device that is to transmit has to wait at least for the
time τ from the last byte recorded on RS-485 bus. If it is to the contrary the first
transmitted byte would be damaged.

3.0 Installation

E06G has to be installed with the respect for specifications of both interfaces.

3.1 Converter connection to RS-232 Interface

Signals assignment to the contacts and DTE-DCE connection is in the table:

abbrev DTE E06G transmit direction
connector connector
SIGNAL (DB9M) (DB9F) DTE E06G

Signal Ground SG 5 5 <> <>
Transmitted Data TxD 3 3 output input
Received Data RxD 2 2 input output
Request to Send RTS 7 7 output input
Clear to Send CTS 8 8 input output
Data Set Ready DSR 6 6 input -­ Data Terminal Ready DTR 4 4 output -­ Data Carrier Detect DCD 1 1 input --