A Modern ModbusPoll Alternative
Everything you need to test and debug Modbus devices - at a fraction of the cost
Looking for a ModbusPoll alternative?
Quick answer: Yes. ModbusBB 2.0 is a Windows Modbus master/client for TCP, UDP, RTU, ASCII and RTU-over-TCP. It covers function codes 01–06, 15 and 16 plus 08, 17, 22, 23 and 43 and can hold several connections at once. It also includes a built-in slave simulator, a raw traffic monitor, scanners, live trends, CSV logging and a CLI. It costs $10 once for a lifetime license on up to 3 devices, with a 30-day free trial.
Modbus Poll from Witte Software is a popular, long-established Modbus master simulator. If you are choosing a Modbus testing tool today, ModbusBB covers the core read/write workflow and adds several simultaneous connections with poll tabs, a raw TX/RX traffic monitor, a built-in device simulator, live trend charts, device/register scanning and a scriptable command-line interface. ModbusBB costs $10 one-time; Witte Software currently lists Modbus Poll at $129 for a single-user license, with the separate Modbus Slave simulator also listed at $129.
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, UDP, RTU, ASCII and RTU-over-TCP. It supports the standard data-access function codes (FC 01-06, 15, 16) plus FC 08, 17, 22, 23 and 43 in Device Tools, and is built for engineers, integrators and technicians who work with PLCs, drives, meters and SCADA systems.
ModbusBB vs. Modbus Poll (Witte Software)
| Capability | ModbusBB | Modbus Poll |
|---|---|---|
| Modbus TCP / RTU | ✔ | ✔ |
| Modbus ASCII | ✔ | ✔ |
| Modbus UDP and RTU-over-TCP | ✔ | See vendor |
| Several simultaneous connections, each with multiple poll tabs | ✔ saved as one workspace (.mbws) | See vendor |
| Core FC 01/02/03/04/05/06/15/16 | ✔ | ✔ |
| FC 08, 17, 22, 23, 43/14 and raw requests | ✔ Device Tools and CLI | See vendor |
| Raw TX/RX traffic view | ✔ filter, pause, CSV/TXT export | See vendor |
| Slave/server simulator in same product | ✔ TCP, UDP, RTU & ASCII, generators, exception injection | No - separate Modbus Slave product |
| Command-line interface (CLI) | ✔ JSON/CSV/NDJSON output, exit codes | Not positioned as a core product feature |
| Live trend charts | ✔ | Different workflow / feature set |
| CSV polling log | ✔ | Logging supported; workflow differs |
| Device & register scanner | ✔ | Check current Modbus Poll feature set |
| Watchdog / value alerts | ✔ log to CSV, sound or write-register actions | Different workflow / feature set |
| Float32 / Int32 with byte order | ✔ ABCD/DCBA/BADC/CDAB | ✔ |
| Float64 / Int64 / UInt64 and String | ✔ | See vendor |
| Built-in device register-map library | ✔ 9 maps (meters, inverters, drives) | See vendor |
| Free trial | ✔ 30 days, 15-min sessions | ✔ 30 days, 10-min connection limit |
| Current listed price | $10 one-time | $129 single-user license |
| License model | Lifetime license; 3 device activations | Perpetual single-user license; vendor upgrade policy applies |
Modbus Poll facts and pricing were checked against Witte Software’s official product, download and ordering pages on 29 Sep 2026. Rows marked “See vendor” were not verified by us. Prices and features can change. Check the official Witte Software store.
What you get with ModbusBB
Master & Simulator
Read/write any Modbus device, and run ModbusBB as a slave to simulate one - no extra tool needed.
GUI + CLI
A modern graphical interface for interactive testing and a command-line tool for scripting and automation.
Multiple devices at once
Several connections open at the same time, each with its own poll tabs, saved together in a workspace. Automatic reconnect with back-off.
All data types
Binary, hex, signed/unsigned 16-bit, Float32, Int32, UInt32, Float64, Int64, UInt64 and String with four byte orders, plus scale, offset and unit.
Traffic & device tools
A raw TX/RX hex traffic monitor, device identification (FC43), diagnostics (FC08), mask write (FC22), read/write multiple (FC23) and raw requests.
Diagnostics
Scan for slave IDs and valid registers, measure response times and loss (CLI stats), and ping devices before connecting.
Logging & trends
Log polled data to CSV, watch values on a zoomable trend chart (CSV/PNG export) and raise watchdog alerts.
Fair licensing
$10 once, use on 3 devices, works offline, free updates for life.
ModbusPoll alternative FAQ
Is ModbusBB a good ModbusPoll alternative?
Yes. ModbusBB is a Windows Modbus master/client that covers the same core job - reading and writing coils and registers over Modbus TCP, RTU and ASCII with the standard function codes. Version 2.0 adds UDP and RTU-over-TCP, several simultaneous connections, a raw traffic monitor, Device Tools for FC 08/17/22/23/43, a built-in device simulator, a command-line interface, data logging and live trend charts, with a free trial and a $10 lifetime license.
Is there a free Modbus master tool?
ModbusBB offers a free 30-day trial with full functionality (15-minute sessions). For unlimited use it is a one-time $10 lifetime license that includes free updates and works on up to 3 devices.
Does ModbusBB support Modbus TCP and RTU?
Yes - Modbus TCP/IP, RTU serial (RS-485/RS-232) and ASCII are supported, plus Modbus UDP and RTU-over-TCP for transparent serial gateways. Serial connections have configurable baud rate, parity, data bits and stop bits.
Does ModbusBB include a Modbus slave simulator?
Yes. The same ModbusBB license includes a built-in simulator that runs as a Modbus TCP, UDP, RTU or ASCII slave/server with several unit IDs, editable registers and coils, value generators and exception injection, so you do not need a separate slave-simulator product.
Try ModbusBB Free
Download the 30-day trial and see if it fits your workflow - no credit card required.