MOD-RS485 development board Users Manual All boards produced by Olimex are ROHS compliant Revision Initial, April 2011 Copyright(c) 2011, OLIMEX Ltd, All rights reserved Page 1
INTRODUCTION: MOD-RS485 is a small module board realized with ADM3483ARZ - low power, differential line transceiver designed to operate using a single 3.3 V power supply, for half-duplex communication. This module can be used to convert RS232 signals into RS485 signals. The board comes with 10 pin cable for the UEXT, via which it can be connected to each of our development boards with UEXT on it.
FUNCTIONAL BLOCK DIAGRAM: Page 3
SCK BH10S 2 4 6 8 10 2 #SS RXD SDA 2 R3 NA 1 2 3 4 VCC B A GND ADM3483ARZ RO /RE DE DI 8 7 6 5 RT 120R 01 TXD SCL UEXT U1 47uF/6.3V/tant 100nF + C2 C1 3.3V 2 1 3 5 7 9 3.3V R2 NA R1 NA 3.3V 1 Page 4 3.3V R4 100R B A TB4/5MM RS485-4 RS485-3 RS485-2 RS485-1 sck 3 ENABLE_RT #ss 3 #SS/SDA 1 SCL/SCK http://www.olimex.com/dev COPYRIGHT(C) 2010, OLIMEX Ltd. Rev. Initial MOD-RS485 R6 NA R5 NA 3.
BOARD LAYOUT: POWER SUPPLY CIRCUIT: MOD-RS485 is power supplied via UEXT connector pin 1 (3.3V) and pin 2 (GND). JUMPER DESCRIPTION: ENABLE_RT This jumper, when closed, enables 120 Ohm termination on the RS485 bus. Default state is closed. SCL/SCK This jumper, when is in position SCL – connects UEXT pin 5 (SCL) to ADM3483ARZ pin 3 (DE) and when is in position SCK – connects UEXT pin 9 (SCK) to ADM3483ARZ pin 3 (DE). Default state is in position SCK.
EXTERNAL CONNECTORS DESCRIPTION: UEXT: Pin # Signal Name 1 VCC 2 GND 3 TXD 4 RXD 5 SCL 6 SDA 7 Not connected 8 Not connected 9 SCK 10 #SS Pin # Signal Name 1 VCC 2 100 Ohm pulldown resistor 3 A 4 B RS485: Page 6
MECHANICAL DIMENSIONS: Page 7
AVAILABLE DEMO SOFTWARE: - Coming soon at our web page: http://www.olimex.
ORDER CODE: MOD-RS485 - assembled and tested board How to order? You can order to us directly or by any of our distributors. Check our web www.olimex.com/dev for more info.
Disclaimer: © 2011 Olimex Ltd. All rights reserved. Olimex®, logo and combinations thereof, are registered trademarks of Olimex Ltd. Other terms and product names may be trademarks of others. The information in this document is provided in connection with Olimex products. No license, express or implied or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Olimex products.
