Simply Modbus TCP Client is a testing and debugging tool for Modbus TCP systems. It uses a licensing model that offers both a free demonstration mode and several paid perpetual license tiers. Simply Modbus Licensing and Pricing All licenses for Simply Modbus

, meaning there are no yearly renewal fees or hidden recurring costs. Modbus Tools Single Program Price Multi-Program Bundle Price 1 User / 1 PC $114 (2 programs) / $162 (3 programs) 2 Users / 2 PCs $204 (2 programs) / $288 (3 programs) Site License $420 (2 programs) / $585 (3 programs)

Note: Bundles typically include the RTU/ASCII Master and Slave emulators alongside the TCP Client. Simply Modbus Free Demo vs. Licensed Version

The software is available for download as a trial. The primary difference lies in the number of requests permitted per session: Demo Version

: Offers full functionality but requires a program restart after sending six read requests or two write commands . It also features a 15-second loading bar upon startup. Licensed Version : Removes the startup delay and allows reads and writes. Simply Modbus Activation Process : Payment is made via the official purchase page : A license key is sent via email from info@simplymodbus.ca . This is a manual process and not instantly automated.

: Upon opening the program, enter the received key into the demonstration startup window and click to activate the full version. Simply Modbus Key Features Ease of Use

: No installation program is required; the software runs directly from a unzipped folder. Versatility

: Functions as a Modbus TCP Master or Modbus RTU over TCP Master. Data Handling

: Supports multiple data types in a single message and allows for Enron Modbus and 2-byte slave IDs. Simply Modbus or configure specific data types within the client? TCP Client Manual 8 | Simply Modbus Software

For Simply Modbus TCP Client, you can obtain a license key directly from the Official Simply Modbus Website. Licenses are sold as one-time purchases and are delivered via email after payment. Pricing for Simply Modbus TCP Client

The software is priced based on the number of users or installations: Single License: $60 USD (for 1 user/PC). Dual License: $108 USD (for 2 users/PCs).

Site License: $225 USD (unlimited installations at one location).

Bundles: You can purchase a bundle of all three programs (RTU Master, RTU Slave, and TCP Client) for $162 USD for a single user. How to Get and Activate Your Key

Download the Demo: You can download Simply Modbus TCP Client to try it first. The demo is fully functional but limits you to six request messages per session. Purchase: Pay via the Purchase Page.

Receive Key: The license key is sent manually by the developer, typically within an hour during MST office hours (Mon-Fri, 8 AM – 4 PM), though it may take longer due to time zones.

Activation: Open the program and click the "Enter Key" button on the initial demo startup screen. Once the key is entered, the 15-second loading delay and message limits are removed. Key Features

No Installation Required: Works as a standalone executable (just unzip and run).

Protocol Support: Functions as a Modbus TCP Master or Modbus RTU over TCP Master.

Troubleshooting Tools: Includes a raw hex dump of network traffic and allows you to log data to text files.

Versatility: Supports multiple data types (16-bit, 32-bit, Enron Modbus) in a single window. Purchase Software - Simply Modbus

Research Paper: An Analysis of Software Licensing Mechanisms and Security Risks in Niche Industrial Applications

Subject: Simply Modbus TCP Client Focus: Licensing Models, "License Key" Circumvention, and Industrial Cybersecurity Implications

4.3 Legal and Compliance Violations

Using unlicensed software violates copyright laws (such as the Digital Millennium Copyright Act in the US). Furthermore, in regulated industries (e.g., energy, critical manufacturing), running unverified software violates compliance standards such as NERC CIP (North American Electric Reliability Corporation Critical Infrastructure Protection).

5. Case Study: The Dangers of Pirated ICS Tools

While specific public breaches involving "Simply Modbus" are not documented, the modus operandi is consistent with supply-chain attacks. If a technician introduces a compromised laptop running a trojanized version of a Modbus client into a critical infrastructure site:

1. Reconnaissance: The malware uses the Modbus client's permissions to map the network.
2. Lateral Movement: The attacker moves from the engineering workstation to the PLCs.
3. Impact: The attacker could manipulate setpoints, causing physical damage to machinery or process disruption.

Step 3: Receive the Key

After payment, you will receive an email containing:

• Your License Key (often a 16 to 20-character alphanumeric string).
• A download link for the registered version (or an unlocker file).
• Instructions based on the version (v8.x, v9.x, etc.).

How Licensing Works

1. Purchase the software from the official website (approx. $59–$79 USD depending on exchange rates).
2. Receive a personalized license.lic file via email (attached or downloadable).
3. Place that file in the application’s installation folder (e.g., C:\Program Files (x86)\Simply Modbus TCP Client\).
4. Restart the application – the license is auto-detected.

There is no key entry dialog box. This is a common point of confusion for users coming from other software (e.g., OPC servers or serial tools).

⚠️ Important: The license is machine-locked to the PC’s hardware ID (derived from the hard drive and network adapter). You cannot share it across multiple computers without purchasing additional licenses.