Never occupies the port
The bundled kernel driver only attaches a filter. Your application keeps the port handle and keeps talking — CommMonitor just watches the traffic.
Serial Port Monitor for Windows
Capture serial traffic without taking the port.
CEIWEI CommMonitor 2026H1 attaches a filter to your COM ports at the driver level, so the software you are debugging keeps the port open while you watch every byte.
- No port occupation
- Native x64 machine code
- Protocol decoding built in
Why CommMonitor
A monitor that stays out of the way
Most serial monitors have to open the port first — which means your own application cannot. CommMonitor works one layer lower.
Native x64 machine code
Built with Delphi 12 Athens for Win64: a native executable with no IL and no managed runtime.
Decodes what you capture
Modbus RTU and ASCII, DL/T 645, IEC 60870-5-101, NMEA 0183 and AT command traffic is decoded as frames arrive.
Explore
Every section has its own page
No anchors, no endless scrolling: the details live on separate pages.
Features
Row filters, export to CSV / JSON / PCAP, redirects to file, TCP or HTTP, and .cms sessions you can hand over.
Protocols
Modbus RTU/ASCII, DL/T 645, IEC 60870-5-101, NMEA 0183 and AT commands, decoded next to the raw bytes.
Dashboard
The same capture in a browser at 127.0.0.1:5000 - frame list, throughput and frame-rate charts, protocol overview.
Download
Current release, file name, size and SHA-256, plus the system requirements before you install.