Modbus — Slave License Key New

If you manage a factory floor with 20+ gateways, you need a strategy for new license deployment:

✅ Have you backed up your old license file?
✅ Did you check if a free upgrade is available (e.g., version 6 → 7)?
✅ Is the software running on the same PC as originally licensed?
✅ Have you disabled VPN / virtual adapters (they change HWID)?
✅ Do you have the order number or invoice from the original purchase?

Most vendors will issue one free replacement key within 12 months. After that, a small admin fee (typically $25–$50) may apply.

When buying a new license, paste that HWID into the order form. This generates a key bound to your PC.

The Modbus protocol itself is an open, public-domain standard and does not require a license or royalty payments . However, specific software tools like Modbus Slave (from Witte Software) or the DEWESoft Modbus Slave Add-On

are commercial products that require registration and a license key for continued use beyond their evaluation periods. Modbus Tools Modbus Slave (Witte Software) License Details Evaluation Period: modbus slave license key new

You are licensed to use the software for evaluation purposes without charge for Trial Limitations:

Early versions had a 4-minute trial period, which was extended to 10 minutes in later releases. Registration:

If you continue using the software after the 30-day period, a registration fee and a valid license key are required. Modbus Tools Acquiring a New License Key

For most commercial Modbus slave tools, the process involves: Requesting a Key: In software like the DEWESoft Modbus Slave Add-On

, you must click "Evaluation license," fill in your details, and submit a request. Activation: If you manage a factory floor with 20+

Once received, the key is entered into the software's license settings. For Modbus Tools

products, you typically enter the registration details provided upon purchase to remove trial limitations. Modbus Tools Report Slave ID (Function Code 17) The term "proper report" in your request may refer to Function Code 17 (0x11) , known as Report Slave ID modbusdriver.com

Allows a master to request a device-specific identifier from a slave. Response Content:

Usually returns a device-specific ASCII string (e.g., product name or version) rather than just a numeric address. Implementation: In custom libraries (like

), you can override a specific method to define the string that is reported back to the master. modbusdriver.com Free & Open Source Alternatives When buying a new license, paste that HWID

If you wish to avoid licensing fees, several open-source Modbus slave implementations are available: FreeModbus

Uses a multi-license approach (BSD/LGPL/GPL) for embedded systems. ModbusTool

A free master and slave test tool available on GitHub that supports TCP, UDP, and RTU. ArduinoModbusSlave A community-driven library for Arduino users. in a particular programming language? Introduction to Modbus TCP/IP - ProSoft Technology

The most notable change is the phase-out of lifetime license keys. New versions of popular Modbus slave simulators now use:

Why the change? Vendors cite enhanced security against key generators ("keygens") and the need to fund ongoing support for new operating systems (e.g., Windows 11 IoT, Linux ARM).

Example: The latest Modbus Slave v9.0 no longer accepts a static license key. Instead, users receive a .slkey file that must be refreshed every 90 days via a vendor portal.

The exact steps vary, but most software follows this pattern: