Document Reference No.: ES_000086

ES-R-2x01B-M RS-232 to RS-422/RS-485 Converters Manual

Version 1.0

Clearance No.: ES

©2010 - 2011 EasySYNC Ltd.

13

Wiring Diagrams

The diagram shows an ES-R-2x01B-M converter connected to an RS-485 half-duplex bus. If the ES-R-

2x01B-M is at one end of the bus (as shown), the built-in resistor can be enabled to terminate the Data

± lines. The Tx ± termination jumper is used to enable this resistor. A second termination resistor is

fitted at the other end of the bus as shown.

If additional unexpected zero bytes are being received, the ES-R-2x01B-M converters also features bias

resistors (not shown below) which can be enabled by enabling the Pull-up Rx+ to VCC by 750 Ohm Bias

resistor and Pull-down Rx- to GND by 750 Ohm Bias resistor) jumpers. For further details see sections

4.1 and 4.4. These should not be enabled if another device on the bus is already providing biasing.

Twisted pair wires are required for each signal pair.

Figure 6

RS-485 Half Duplex Wiring

RS-485 Devices

ES-R-2x01B-M

Data+

Data-

GND

Data+

Data-

GND

Data+

Data-

GND

Data+

Data-

GND