Everything you need to test and debug Modbus devices - at a fraction of the cost
ModbusPoll is a popular, well-established Modbus master simulator - and if you already own it, it does the job. But if you are choosing a Modbus testing tool today, ModbusBB gives you the same core capabilities plus modern extras like a built-in device simulator, live trend charts and a command-line interface, with a free trial and a $10 one-time lifetime license instead of a recurring or higher up-front cost.
ModbusBB is a professional Modbus master/client for Windows 10 and 11. It reads and writes coils, discrete inputs, holding registers and input registers over Modbus TCP, RTU and ASCII, supports all standard function codes (FC 01-16), and is built for engineers, integrators and technicians who work with PLCs, drives, meters and SCADA systems.
| Capability | ModbusBB | Typical Modbus Master Tool |
|---|---|---|
| Modbus TCP / RTU | ✔ | ✔ |
| Modbus ASCII | ✔ | Sometimes |
| All function codes (FC 01-16) | ✔ | ✔ |
| Built-in device simulator (slave) | ✔ TCP & RTU | Separate paid tool |
| Command-line interface (CLI) | ✔ | Rare |
| Live trend charts | ✔ | Sometimes |
| Data logging to CSV | ✔ | Sometimes |
| Device & register scanner | ✔ | Sometimes |
| Watchdog / value alerts | ✔ | Rare |
| Float32 / Int32 with byte order | ✔ ABCD/DCBA/BADC/CDAB | ✔ |
| Free trial | ✔ 30 days | Varies |
| Price | $10 one-time, lifetime | Higher / recurring |
| Free lifetime updates | ✔ | Varies |
Comparison reflects ModbusBB's capabilities versus common Modbus master tools. Feature sets and pricing of other products vary by version and vendor.
Read/write any Modbus device, and run ModbusBB as a slave to simulate one - no extra tool needed.
A modern graphical interface for interactive testing and a command-line tool for scripting and automation.
Binary, decimal, hex, Float32, Int32, UInt32 with selectable byte order for 32-bit values.
Scan for slave IDs and valid registers, measure response times, and ping devices before connecting.
Log polled data to CSV and watch values live on a real-time trend chart.
$10 once, use on 3 devices, works offline, free updates for life.
Download the 30-day trial and see if it fits your workflow - no credit card required.