Download the latest version from the official Modbus Tools website ( modbustools.com ). Run the installer and follow the on-screen instructions.
Select (this option appears if the software is not yet registered).
: The application closes automatically after 10 minutes of continuous connection.
), the software will prompt you to enter your license key if it is not already registered. Via Help/About : You can often find registration options within the (F1) sections of the user interface. Modbus Tools Licensing and Evaluation Details Trial Period : You can use the software for free for Demo Mode Limits : During the trial, each connection session is limited to 10 minutes Registration Key Modbus Poll
Obtaining a Registration Key Modbus Poll is a straightforward process:
Open Modbus Poll from your desktop shortcut or Start Menu.
| Function Code | Description | |---------------|-------------| | 01 (0x01) | Read Coils | | 02 (0x02) | Read Discrete Inputs | | 03 (0x03) | Read Holding Registers | | 04 (0x04) | Read Input Registers | | 05 (0x05) | Write Single Coil | | 06 (0x06) | Write Single Register | | 08 (0x08) | Diagnostics (serial only) | | 11 (0x0B) | Get Comm Event Counter (serial only) | | 15 (0x0F) | Write Multiple Coils | | 16 (0x10) | Write Multiple Registers | | 17 (0x11) | Report Server ID (serial only) | | 22 (0x16) | Mask Write Register | | 23 (0x17) | Read/Write Multiple Registers | | 43/14 (0x2B/0x0E) | Read Device Identification | Download the latest version from the official Modbus
If you have recently searched for a you are likely facing the 30-minute runtime limitation of the trial version or looking for a way to unlock the full feature set without paying the licensing fee. This article will explain what a legitimate registration key is, the severe dangers of using cracked or unauthorized keys, and how to legally obtain full functionality.
It is easy to resent paying for a tool you use occasionally. However, the license fee supports:
: You can test all features for free for 10 minutes per session before needing a key. : The application closes automatically after 10 minutes
A Modbus Poll registration key is a unique alphanumeric string provided by the software developer, Witte Software. This key unlocks the full potential of the software, converting the trial version into a licensed, permanent copy. Why You Need a License Key
for up to two licenses, with discounts for volume purchases (e.g., $119.00 for 3–9 licenses). Official Merchant : You can purchase keys directly from the Witte Software Ordering Page Activation Process : Obtain the software from the official Modbus Tools download section Open Registration
The trial version implements a , after which the connection automatically disconnects. While this limitation exists to encourage licensing, the full feature set remains accessible throughout the trial. After disconnection, simply reconnect to continue testing.