Modern software for
industrial communications.
Modern diagnostic and engineering tools for industrial communications - starting with Modbus.
Highlighted orders decode to a plausible value - click to apply.
- Function code
- 0x03 · Read Holding Registers
- Word count
- 2
- Display type
- F32 · ABCD
- Polled
- every 500 ms
The protocols are fine.
The tools around them are not.
The small utilities every engineer reaches for - Modbus scanners, serial sniffers, register pokers - look and feel like they did fifteen years ago. They work. They're also clunky, ugly, and well below the standard of any other professional software in 2026.
We're working engineers, and Coilware exists to fix that - better versions of the tools we already use every day, built to the standard the rest of our software stack hit a decade ago.
Diagnostic tools, designed.
Live register table
Holding, input, coil, discrete - typed, scaled to engineering units, annotated, polled. Edit cells in place. Watch each value trend on an inline sparkline.
Frame inspector
Every TX/RX frame, decoded. MBAP/CRC validated, function code named, payload explained. Export the whole capture to .pcapng and open it in Wireshark.
Byte-order decoder
Expand any register to see all four byte orders - ABCD, CDAB, BADC, DCBA - decoded side by side. Flip the order inline and the value resolves instantly.
Scripted polling
A real CPython 3.12 runtime with a pre-bound client object - the full standard library, not a macro recorder. Write conditional logic, threshold checks and unattended loops in actual Python.
Server simulator
Stand up a Modbus TCP slave with no hardware. Multiple unit IDs, all four register banks, live value animators - sine, ramp, random-walk, counter - and on-demand exception injection to test your master's error paths.
Portable build
No-install portable zip - unzip and run, no admin rights. Made for the locked-down plant laptop IT set up in 2017. (Installer also available.)
The Modbus Debugging Field Manual.
A free, practical guide to debugging Modbus on real plant networks - exception codes, byte-order traps, and the fixes that actually work. We're writing it now. Join the list and we'll email you the day it ships.
Things we wrote down.
Modbus function codes: reads, writes, and why some are read-only.
The major Modbus function codes (01-06, 15, 16) - what each one targets, real examples of the data they carry, and why the protocol splits read-only and read-write into separate tables.
Modbus byte order explained: ABCD, CDAB, BADC, DCBA decoded.
How 32-bit floats and integers sit across two Modbus registers. Every byte-order variant (ABCD, CDAB, BADC, DCBA) explained, plus the field workflow to identify yours.
Modbus exception codes explained: every code and how to fix it.
Every Modbus exception code (Modbus RTU and Modbus TCP), what each one really means in practice, and how to chase it down with a frame capture.
Twenty perpetual licences.
Honest feedback in exchange.
We're opening a limited beta on 1 July 2026 - and taking applications now. First twenty engineers get a free perpetual licence in exchange for bug reports and feature requests.