Table of Contents

Introduction

Starting Modsak

Screen layout

Using Modsak

Setup overview

Master mode

Slave mode

Monitor mode

Configuration

Configuration dialog

Saving and restoring the configuration

Settings

General settings

Note on limits on Modbus message sizes

Interface settings

Address mapping

Types of address

Defining address ranges

Overlaying address ranges

Special registers

Example address mappings

32/64-bit Value Settings

Polling Settings

Device Identification

Read Device Identification (43/14) command

Report Slave ID (17) command

Registers

Defining registers

Register display

Editing register definitions

Deleting register definitions

Saving and restoring register definitions

Commands

High-level command sending

Read & Write buttons

Define Command panel

Polling

Implementation

Defining commands

Introduction

Low-level commands

Custom commands

Sending raw data

Command table

Sending commands

Deleting commands

Re-ordering commands

Editing command definitions

Tracing and logging

Introduction

Raw data tracing

Message tracing

Register logging

Saving and clearing trace output

Troubleshooting

Introduction

Communications

General

Socket Communications

Serial Communications

RTU Packet Type

ASCII Packet Type

TCP Packet Type

Master Mode

Slave Mode

Monitor Mode

Miscellaneous

Appendix A. Screenshots

Appendix B. Modbus protocol documents

Appendix C. CSV file format