The complete COM-port testing suite. Monitor live traffic, generate standard or custom patterns, inject errors on demand — and let the smart-alignment comparator point at the exact byte that went wrong.
Baud rate, data bits, parity, stop bits and flow control — configure any RS-232 or RS-485 link exactly to spec.
Standard test patterns — incrementing, walking bits, PRBS and more — at your chosen rate and length.
Define your own byte sequences to reproduce a specific protocol frame or a known-bad payload.
Live RX/TX byte counts, throughput and timing — see exactly what’s crossing the wire as it happens.
Deliberately introduce parity, framing and data errors to test how your device handles corruption.
Full breakdown of transfers, error types and counts — the evidence you need to sign off a link.
Verify cabling and adapters instantly with a built-in loopback test before you trust the link.
Send a known pattern, capture what arrives, and let the comparator do the staring for you.
Automatically aligns sent and received streams even when bytes are inserted or dropped — a single glitch doesn’t cascade into thousands of false mismatches.
Every mismatch highlighted in a clear hex view — no squinting at raw logs.
Jump straight from one error region to the next to triage corruption fast.
Loopback clears the adapter, then pattern tests across the real cable at increasing baud rates. In ten minutes you know which link drops bytes — with statistics to prove it.
Soak-test every RS-485 drop with continuous patterns overnight. The error report tells you which terminals need rewiring while it’s still cheap to fix.
Inject parity and framing errors on purpose and watch how the device under test recovers. Firmware that only ever saw clean input fails in the field — this finds it in the lab.
Send a known pattern through a USB-serial converter or serial-to-IP gateway and diff what arrives. Latency, dropped bytes and silent corruption all show up in one view.
Click any screenshot to zoom.
Validate PLC, SCADA and Modbus links on the plant floor before commissioning.
Debug UART traffic and firmware serial protocols during bring-up and testing.
Diagnose flaky cabling and adapters on site with loopback and error injection.
Learn RS-232/RS-485 fundamentals with real, observable serial traffic.
Free for Windows — today, and always.
No license, no registration, no expiry.
| OS | Windows 10 / 11 (64-bit) |
| Interfaces | RS-232, RS-485 (any Windows COM port) |
| Patterns | Incrementing, walking bits, PRBS, custom byte sequences |
| Error injection | Parity, framing, data errors on demand |
| Analysis | Smart-alignment comparator · statistics & error reporting |
| License | Free — no commercial license required |