ModbusBB is a Windows Modbus master/client, slave/server simulator and command-line tool for SCADA and automation engineers testing PLCs, meters, inverters, drives and gateways.
Connect to multiple devices over TCP, RTU, ASCII, RTU-over-TCP or UDP. Read/write coils and registers, inspect raw TX/RX frames, decode 16/32/64-bit values and strings with selectable byte order, scaling and units, and use FC08/17/22/23/43 device tools.
Simulate devices with value generators, exceptions and delays. Scan devices/registers, plot trends, log CSV data, configure watchdog alerts and automate tests with CLI JSON/CSV output.
Free 30-day trial: all features, 15-minute sessions. $10 USD lifetime license: unlimited session time, one user on up to 3 computers, free updates. License activation and verification at least every 30 days require internet access.
Published by Max Energic Apps. Docs: https://modbus.maxenergic.com/docs.html
Features
- Modbus TCP, RTU, ASCII, RTU-over-TCP and UDP
- Multiple simultaneous connections, each with multiple poll tabs
- Raw TX/RX traffic monitor (hex + ASCII) with filter, pause and export
- Auto-reconnect with backoff, configurable retries and timeouts
- Float32/64, Int16/32/64, UInt16/32/64, String, Hex, Binary - 4 byte orders
- Scaling, offset, units and engineering values; Modicon address notation
- Device Tools: FC43/14 device ID, FC17, FC08, FC22 mask write, FC23, raw requests
- Register-map library for common energy meters, inverters and drives
- Slave simulator: TCP/UDP/RTU/ASCII, multiple unit IDs, generators, exception injection
- Live trend chart with zoom/pan and CSV/PNG export
- Watchdog alerts with actions: CSV log, sound, write register
- Scriptable CLI: JSON/CSV output, --trace, exit codes, workspace run, simulate
- Workspaces, slave & register scanners, CSV data logging, dark/light theme