ICPDAS SG-785 User Manual

SG-785 Hardware User Guide

Ver. 1.0

Last Modified 10/26/2009

Introduction

The SG-785 is an optional module that is used to improve the communication
of RS-485 network. It provides switch selectable pull-high and pull-low
resistors on RS-485 network. It also has 15-step switch selectable termination
resistor such that the user can select a proper termination resistor to be
connected to the RS-485 network easily.

Specifications

General

Interface RS-485
Pull-high/pull-low Resistance 1k Ω
Termination Resistance 15 steps, 65 ~ 560 Ω

LED Display

1 red LED as power indicator
1 green LED as termination indicator

Power

Input Range 10 ~ 30 VDC
Power Consumption 0.5W, 24 VDC

Environment

Operating Temperature -25 °C ~ +75 °C
Storage Temperature

-40 °C ~ +80 °C

Humidity 5 ~ 95 % RH, non-condensing

SG-785 Pin Assignment

LED Display

PWR Power LED, Red
TR Termination Resistor LED, Green

Switches

TR Termination Resistor Setting
SW Termination Resistance and Pull-high/Pull-low Setting

Terminal Block

(Y)DATA+, (G)DATA- RS-485 Data Line
(R)+Vs, (B)GND Power Line
F. G. Frame Ground