Table of Contents

Introduction

Starting ModTest

Screen layout

Using ModTest

Setup overview

Configuration

Configuration options

Saving and restoring the configuration

Settings

General settings

Note on limits on Modbus message sizes

Interface settings

32/64-bit Value Settings

Commands

Defining commands

Introduction

Standard commands

Custom commands

Sending raw data

Command table

Sending commands

Deleting commands

Re-ordering commands

Editing command definitions

Testing commands

Tracing

Introduction

Raw data tracing

Message tracing

Saving and clearing trace output

Troubleshooting

Introduction

Communications

General

Socket Communications

Serial Communications

RTU Packet Type

ASCII Packet Type

TCP Packet Type

Sending commands

Appendix A. Screenshots

Appendix B. Modbus protocol documents