Download ModbusBB 2.1.0

Release notes

What's new in 2.1.0

• Stronger licensing: on activation the license server issues a digitally signed (Ed25519) license file for this computer. ModbusBB checks it offline, so a modified key or a fake server answer can't unlock it
• The license is re-checked online every 7 days; without internet ModbusBB keeps working for up to 30 days after the last successful check
• Same license key, same 3-computer limit and same license portal as before. After updating, ModbusBB needs internet once to get its license file

What's new in 2.0.2

• The Simulator (Data View and generator Format column) and the Watchdog editor now show UInt16, Int16 and Hex like the register grid, instead of internal names such as "UnsignedDecimal"
• CLI: the format field in read --output json and the map show table now use the --format names (uint16, int16, hex, float32, …). Scripts that matched the old values need updating
• The built-in simulator's device identification (FC43/14) reports the real ModbusBB version instead of a fixed "2.0.0"
• When a 15-minute trial session ends, the message now says "Trial Session Ended" and explains how to start a new session
• Website: the top menu no longer wraps on laptop screens

What's new in 2.0.1

• The simulator now answers FC43/14 Read Device Identification and FC17 Report Slave ID
• Fixes for update-announcement emails

What's new in 2.0.0

Connections and workspaces

• Multiple simultaneous connections, each with any number of poll tabs that can all run at the same time
• New transports: RTU-over-TCP and Modbus UDP, alongside TCP, RTU and ASCII
• Retries per request (default 3) and automatic reconnect with exponential back-off. Polling resumes after the link returns
• Workspaces (.mbws) save connections, polls, register settings and watchdog rules, with a recent-files list and optional auto-connect. 1.x profiles (.json/.mbprofile) and .mbcfg files open directly
• Poll intervals now go up to 1 hour (100 ms minimum)

Decoding and addressing

• New data types: Float64, Int64, UInt64 and String, with ABCD/DCBA/BADC/CDAB for all multi-register types
• Per-row format, byte order, scale, offset and unit, with an engineering value column
• Address notation: 0-based, 1-based or Modicon (0xxxx/1xxxx/3xxxx/4xxxx)
• Rows read with FC02/FC04 are read-only, and inputs are validated before sending

Diagnostics

• Traffic monitor: raw TX/RX frames in hex with filter, pause, copy and CSV/TXT export
• Device Tools: FC43/14 Device Identification, FC17 Report Slave ID, FC08 Diagnostics, FC22 Mask Write, FC23 Read/Write Multiple, and a raw request for any FC 1-127
• Device library with 9 register maps (Eastron SDM120/SDM630, Schneider PM5xxx, Carlo Gavazzi EM24, SunSpec Common, Growatt, SMA, ABB ACS580, Schneider Altivar). Each lists its source and a note to verify it against the device manual
• Slave scan counts devices that answer with an exception as found

Simulator, trend and alerts

• Simulator: TCP, UDP, RTU and ASCII with full serial settings, multiple unit IDs, value generators (static, ramp, sine, random, counter, toggle), exception injection and response delay/jitter
• Trend chart: multi-series, zoom/pan, configurable history, CSV and PNG export
• Watchdog: rules on engineering values with debounce, cooldown and transition-only firing. Actions can log to CSV, play a sound or write a register/coil. Alerts appear in a non-blocking Alerts tab

Command line

• One-shot, scriptable commands with inline connection options: read, write, poll, scan, stats, devid, slaveid, diag, maskwrite, rw, raw, library, workspace run and simulate
• --output table|json|csv (NDJSON for poll), --trace hex frames, --dry-run, and exit codes 0/1/2/3/130. See the CLI reference

Security and licensing

• Update links only open the official HTTPS download page. Published SHA-256 checksums let you verify each download
• Licenses are verified online per device (up to 3 devices), with a 30-day offline grace period

Upgrade

Upgrading from 1.x

Details: Upgrading from 1.x.

Download FAQ

Is the trial really free?

Yes. You get 30 days with every feature and 15-minute sessions. No credit card is required.

Does my 1.x license key work with 2.0?

Yes. Install 2.0 over your current version and start it once with an internet connection. The stored key is found and re-activated for that PC. Existing keys keep working at no extra cost.

What are the system requirements?

64-bit Windows 10 or 11. The build is self-contained with the .NET 8 runtime included, so nothing else needs to be installed. Plan for about 250 MB of disk space; 4 GB RAM is recommended.

Installer or portable: which should I get?

Both contain the same GUI and CLI. The installer adds Start-menu shortcuts and can add the CLI to PATH. The portable ZIP runs from any folder or USB stick with no installation.

How do I verify the download?

Compare the file's SHA-256 hash with the checksum on this page. Use Get-FileHash in PowerShell or certutil -hashfile in cmd.

How do I activate after buying?

Your license key arrives by email. Start ModbusBB, paste the key in the license window and activate (internet required). It works on up to 3 devices and keeps working offline for up to 30 days between online checks.

New to Modbus? Start with Learn Modbus and the guides, or see how ModbusBB compares as a ModbusPoll alternative.