ModSlaveSim - Programmable Modbus slave simulator

ModSlaveSim is a programmable simulator that enables realistic simulation of a Modbus slave in its environment. Connect your Modbus masters to ModSlaveSim, instead of a real Modbus slave device, in order to test and configure the masters.

Using a simple control language you can simulate a Modbus slave measuring environment properties (e.g. flow rate), controlling the environment (e.g. opening valves), performing internal calculations (e.g. averages), and responding to Modbus commands from masters.

ModSlaveSim displays the Modbus device registers as they change, and provides a trace of Modbus messages between slave and masters. It also has a troubleshooting facility.

ModSlaveSim's other main features are:

  • Full support for coils, discrete inputs, input registers and holding registers, using commands 1, 2, 3, 4, 5, 6, 7, 8, 11, 15, 16, 17, 22 and 23.
  • Supports network and serial (RS232/RS422/RS485) interfaces using the Modbus/TCP, RTU and ASCII protocol variants.
  • Cross-platform: runs on any system that supports Java 1.4 or later - including Windows, Linux, Solaris and AIX.
  • All known extensions of the Modbus protocol for handling 32-bit and 64-bit integers and floating-point numbers are supported (including Enron/Daniels Modbus).
  • Can transfer a mixture of integers and floats, of different sizes, in a single message.
  • Flexible address mapping allows separate or overlaid address spaces (for coils, discrete inputs, input registers, and holding registers) with arbitrary bases.
  • Registers are individually configurable for type (integer or float), size (16/32/64-bit), and radix (binary, octal, decimal, or hex).
  • Supports broadcast requests (slave ID 0).
  • Can trace all Modbus messages sent and received.
  • All configuration settings and register definitions may be saved to and restored from files.
  • Online manual/HOWTO/troubleshooting facility.
  • Online example simulations in ModSlaveSim.

ModSlaveSim main window

You can download the complete version of ModSlaveSim for a FREE 3-DAY EVALUATION PERIOD - read on for details.

Downloading and installing ModSlaveSim

Since ModSlaveSim is written in Java, you will need a copy of the Java JRE (version 1.4 or later) in order to run it.

To install ModSlaveSim simply download the file modslavesim1.11.jar from the products page, and put it in any convenient directory/folder.

To run ModSlaveSim, use the command:

java -jar modslavesim1.11.jar

You will, of course, need to use the full pathname for modslavesim1.11.jar if it's not in your current directory/folder. You will probably want to create a shortcut, launcher, shell script, or whatever to save you having to keep typing the above command.

If you get an error from the "java -jar modslavesim1.11.jar" command, try the command:

java -version

If you get an error from this command, then you do not have the JRE installed, and you will have to download it (see Getting Java).

Before you can use ModSlaveSim you will need to get a registration key.

Problems?

If you have any problems setting up the Java environment, installing ModSlaveSim, getting a registration key, or using ModSlaveSim, please email us at support@wingpath.co.uk and we will do our best to help.

If you are reporting a bug, please give a full description of what you were doing and what went wrong. Include all the information displayed in the Help->About dialog, and also any output that was sent to the command window.