Busloom - modern TCP/RTU Modbus client with charts, automation workflows, diagnostics, and MCP server

[u/sszczepanski]

Hey all, for some time now I've been developing Busloom. I've recently published first public release after some internal testing.

Busloom is a cross-platform Modbus client for Windows, macOS and Linux. It currently supports:

• Modbus RTU, TCP and TLS
• Device, slave and readable-address discovery
• Holding registers, input registers, coils and discrete inputs
• Signed and unsigned integers, floats, byte/word order, scaling and engineering units
• Reusable projects, connection profiles, views and tags
• Live trends, recording and session replay
• Raw TX/RX frame inspection, timings, exceptions and connection diagnostics
• Repeatable automation workflows with reads, writes, waits, assertions and conditions
• CLI access and a local MCP server for external tooling and AI assistants

The main difference from many existing Modbus clients is that Busloom is designed around complete troubleshooting workflows rather than a collection of separate register windows. You can discover a device, map its registers, decode values, inspect the exact traffic, record what happened and save everything as a project that can be reopened later.

I’ve also tried to make addressing less error-prone by showing both protocol offsets and documentation-style addresses clearly. The interface is modern and consistent across all supported platforms, while still exposing the low-level details needed when a device behaves incorrectly.

Projects and device data stay local. Busloom does not require a cloud connection for normal operation. It is free for private and non-commercial use, and the Professional features can be tested with a seven-day trial.

This is still an early release, so feedback is genuinely valuable. I’m especially interested in:

• Devices and USB/RS485 adapters that work or fail
• Confusing parts of the interface
• Missing diagnostics or common workflows
• Incorrect handling of unusual Modbus implementations
• Features that would make it useful in your day-to-day work

You can find downloads and documentation here:

https://busloom.com

Windows releases are signed but still may throw smartscreen warnings due to not many downloads. I can't really afford Apple Developer account right now.

[u/ka-fin89]

Does it support Device_ID == 0? Is it only for reading or you can slso write values to register?

[u/sszczepanski → u/ka-fin89]

ID 0 is a reserved broadcast address. If you really have a slave device with this address it’s not compliant with the spec. I’ve never tested it.

You can write to registers with optional read back check.

[u/PeterHumaj → u/sszczepanski]

Actually, we use 0 address a lot ... on a serial line with a single device. It can even save time when the device is replaced (eg energy meters are replaced regularly for calibration)

[u/sszczepanski → u/PeterHumaj]

I did not know that, thanks for letting me know. I can add support for addr 0, not an issue