Document Reference No.: ES_000011
ES-R-2x01-M RS232 to RS422 / RS485 Converter User Guide
Version draft
Clearance No.: ES#*
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©2009 EasySync Ltd.
4
1
Introduction
1.1
Functional Description
The ES-R-2001-M and ES-R-2101-M are RS232 to RS485 / RS422 adapters that support transfer rates up
to 1M baud. The two models are identical, except that the ES-R-2101-M includes optical isolation
between the RS232 and RS422 / RS485 connections.
With RS422 mode selected the interface can be configured for four-wire operation with CTS / RTS
hardware handshaking. In RS422 mode the transmitter is always on.
With RS485 mode selected the interface can be configured for four-wire full duplex operation or two-wire
half duplex operation with optional echo back. The transmitter enable is controlled automatically with a
turn-around delay of less than 20us.
Optional RS422 / RS485 termination and bias resistors can also be configured.
The RS232 interface on the ES-R-2x01-M can be configured to be a DCE or a DTE type. The default link
settings select a DCE type which allows use of a straight-through DE-9S to DE-9P cable.
1.2
LED Description
The ES-R-2x01-M uses three LEDs to indicate power and data activity. The table below defines the LED
functions.
LED Colour
Function
Description
Yellow
Power
Power is being supplied to “DC-IN”
Green
TxD
Shows data activity from RS232 to RS422 / RS485
Red
RxD
Shows data activity from RS422 / RS485 to RS232
Table 1.1 – LED Description
1.3
Features
•
Converts RS232 signals to RS422 or RS485 differential signals
•
Easy installation
•
Power supply provided
•
ES-R-2101-M provides TBD KV of optical isolation, including power supply
•
Metal case with mounting tabs
•
Optional DIN rail clips
•
DE-9P connector and screw terminals for a variety of RS422 and RS485 connections
•
Termination available through jumpers inside case
1.4
Performance Figures
Parameter
Performance
Asynchronous Speed
Up to 1Mbps
Table 1.2 – Performance Figures
Preliminary
