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Modbus RTU/ASCII Slave Tool

RTU/ASCII Slave Tool Screenshot

Overview

This test tool allows your Windows PC to simulate a Modbus RTU or Modbus ASCII slave device.

It is used to test, troubleshoot, and monitor Modbus serial communication.


It monitors a serial port looking for an incoming request message from a Modbus Master.
Once received, it builds and sends a reply using data from it's tables.

Slave Data window

Key Features

  • Functions as a Modbus RTU Slave or Modbus ASCII Slave
  • Replies to an RTU or ASCII master device when querried.
  • Settings are entered and displayed in one window with a 2nd window for the data
  • Supports Standard Modbus and Enron Modbus registers
  • Supports adding random noise to emulate live data
  • Supports responding to all slave IDs to simulate many slaves
  • Save and restore settings in configuration files
  • Save Byte History Log to a text file

16 bit Register Function Codes

Function Code Action
04 Read Input Registers
03 Read Holding Registers
06 Write Single Holding Register
16 Write Multiple Holding Registers

1 bit Coil Function Codes

Function Code Action
02 Read Discrete Inputs
01 Read Coils
05 Write Single Coil
15 Write Multiple Coils

Download

The free download has full functionality and runs in demonstration mode until licensed.
Demonstration mode had full functionality but limits sending of response messages to the master to six.
It can then be restarted to send more messages.
Download and run in demonstration mode. Try before you buy.

System Requirements:
Windows NT, 95, 2000, XP, Windows7, Windows8, Windows10 & 11
display resolution: 800 x 600 minimum
PC with serial port (built in, serial card or USB serial port)

Download

Simply Modbus RTU/ASCII Slave 8.1.3

Looking for older versions of the software?    View previous site

Purchase

Licenses are available for single users, multiple users, or site licenses.

Purchase License

Documentation

View Manual
Next: Slave Manual