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Table of Contents

Introduction

Serial Communications Basics

RS232

RS422

RS485

UART Wildcard Hardware

Connecting To Mosaic Controller

Selecting the Module Address

RS422/485 Configuration Jumpers

Protocol Configuration and Direction Control Registers

Modem Handshaking Signals

UART Module Field Header

Cable Connections

Software

Overview of the Software Device Driver Functions

Installing the UART Module Driver Software

Using the Driver Code with C

Using the Driver Code with Forth

UART Direction Control in a Multitasking System

Glossary

Overview of Glossary Notation

Glossary Quick Reference

Glossary Entries

C Demonstration Program (in pdf)

Forth Demonstration Program (in pdf)

Hardware Schematics (in pdf)

UART Wildcard User Guide

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Cable Connections

This section presents some suggested cable connections for common protocols. Each application will typically require a custom cable assembly to meet the needs of that project.

Table 1-5 Cable for Dual RS232 25-pin D Connectors

UART Wildcard: cable for dual RS232 connector

Table 1-5 illustrates the connections required to implement two RS232 ports, each using a standard 25-pin D-type connector. Note that TxD at the local UART Wildcard connects to RxD at the remote, and the local RxD connects to TxD at the remote. Also note that the RS232 handshaking signals RTS and CTS are connected to each other with a shorting wire at the D connector. Similarly, the RS232 handshaking signals DSR and DTR are connected to each other at the D connector. This standard scheme makes the remote computer think that it is always OK to send and receive data.

A cable that supports a modem on channel 1 is shown in Table 1-6. Note that the handshaking signals are brought out to the 25 pin D-connector. The CTS1 (clear to send) input to the UART Wildcard connects to the RTS (ready to send) output from the remote. The DSR1 (data set ready) input to the UART Wildcard connects to the DTR (data terminal ready) output from the remote. The DTR1 and RTS1 outputs from the UART Wildcard connect to the DSR and CTS inputs to the remote, respectively. The DCD (data carrier detect) modem output connects to the RxD2/DCD1 input on the UART Wildcard. Because this pin is shared with RxD2, Channel2 cannot be configured for RS232 when a modem is in use. In this case, the user is free to implement RS422 or RS485 on Channel 2.

Table 1-6 Cable for an RS232 Modem via a 25-pin D Connector

UART Wildcard: cable for dual RS232 via 25 pin connector

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