FOR AUTOMATION & EMBEDDED ENGINEERS

Serial & Modbus debugging,
with an AI that reads hex.

Raw serial, Modbus RTU/TCP master & slave — one app, one timeline. Select any broken frame and the AI tells you what it is, why it failed, and what to check next.

Download for Windows — Free 60 seconds to first frame
Windows 10/11 · 64-bit · Portable .zip available · No account required · Free forever tier
The moment that used to cost you an afternoon.
FROM MANUAL TO POLLING IN 60 SECONDS

New device? Skip the typing.

STEP 01

Paste the manual

Screenshot the register map from any device manual. The AI extracts addresses, types, byte order, scaling and units into a point map.

STEP 02

Review & poll

You confirm the address base and any flagged rows — nothing imports silently. One click builds segmented poll tasks and starts reading real values.

STEP 03

Ask why it broke

CRC fail, exception code, garbage bytes, timeouts — select the frame and get ranked causes plus a checklist, right where the error happened.

THE WORKBENCH

One timeline for everything on the wire.

Unified frame timeline

Raw serial and parsed Modbus share one spine: microsecond timestamps, response latency (Δ) per exchange, byte-level field coloring, filter and export.

AI frame explanation

The first protocol tool that reads hex back to you: what the frame is, which byte is wrong, the most likely cause, and what to check next.

AI point map import

Manual screenshot → typed, scaled, named register grid. Address-base confirmation and conflict checks make it safe, a device profile makes it reusable.

Master & slave, one app

Poll real devices and simulate them — with sine/increment value generators — in the same window. Loop them back to test your own software with no hardware.

Bus monitor & auto-detect

Clip passively onto a live 485 bus. Fieldbench splits the stream, runs CRC heuristics and offers one-click Modbus decoding of the entire history.

Truly offline

Activate once — online or fully offline — and it never phones home. Portable .zip for locked-down factory PCs. Only the optional AI needs a network.

HONEST COMPARISON

Built for what the old tools can't do.

Capability
Fieldbench Pro
Modbus Poll + Slave
ModbusSimulator
Master + slave in one app
2 products
Raw serial terminal in same timeline
Passive 485 bus monitoring + auto-detect
AI frame explanation
AI point map from manual screenshot
Fully offline activation
online
Price, one-time
$99
$129 × 2
$99
Competitor details from public pricing pages, July 2026. Corrections welcome — we'll fix them.
PRICING

Buy once. Own it forever.

The tool is a one-time purchase. AI is an optional add-on — it burns metered API capacity, so it's the only thing that subscribes.

Free

$0
forever
  • 1 active connection
  • Full Modbus master, all function codes
  • Timeline, byte inspector, slave scan
  • AI trial: 30 explains + 3 extractions
  • Charts limited to 2 channels
Download free
No account. No email. Just the .exe or .zip.
LAUNCH · 30 DAYS

Pro

$69$99
one-time · yours forever · 2 devices
  • Unlimited connections & sessions
  • Slave simulation with value generators
  • Unlimited chart channels + CSV export
  • Offline activation, no phone-home ever
  • Free 1.x updates · priority support
Buy Pro — $69
30-day money-back · VAT handled at checkout by Paddle

AI Assistant

$49
per year · or $6.9 monthly
  • 1,000 frame explanations / month
  • 30 point map extractions / month
  • Works on Free or Pro
  • Frames sent only when you press Explain
  • Nothing stored on the gateway
Add AI Assistant
Cancel anytime · core app unaffected
Launch bundle: Pro + one year of AI for $99 (regular $119) — the whole workbench, under a hundred bucks.
✓ 30-day money-back guarantee✓ Invoices for company reimbursement✓ Merchant of record: Paddle
QUESTIONS ENGINEERS ACTUALLY ASK

FAQ

Does it work offline?

Yes — every core feature works with zero network. Activation has a fully offline path (machine code → activation file), and once activated the app never phones home. Only the optional AI assistant needs a connection; when you're offline its button simply grays out.

Is this a subscription?

No. Fieldbench Pro is a one-time purchase you own forever, including all 1.x updates. The AI assistant is the only subscription, because every explanation consumes metered API capacity — and the app is fully usable without it.

How is it different from Modbus Poll?

Modbus Poll and Modbus Slave are two separate $129 purchases with an interface from another era. Fieldbench puts master, slave and raw serial in one timeline, can passively monitor a live bus, auto-detects Modbus, explains broken frames with AI, and imports register maps from manual screenshots.

Windows says "unknown publisher"?

It shouldn't — installers and the portable build are code-signed. If SmartScreen still shows a prompt on a fresh release, "More info → Run anyway" is safe; the signature details will show Fieldbench as publisher.

Can my company reimburse this?

Yes. Checkout is handled by Paddle as merchant of record — you get a proper invoice with VAT/sales tax handled for your country. Most engineers simply expense it.

What's the refund policy?

30 days, no questions asked. If Fieldbench doesn't save you time, you shouldn't pay for it.

Your next site visit deserves better tools.

Free forever for single-connection work. Sixty seconds to first frame.

Download for Windows