A marine navigation system integrates a GPS receiver outputting 10Hz NMEA sentences. The engineer uses Serial Bandwidth Monitor 3.4 to log a 24-hour trace. The tool’s bandwidth graph reveals periodic drops to zero – correlated with satellite constellation changes. This data justifies switching to a multi-constellation GNSS receiver.
One of the most praised aspects of Serial Bandwidth Monitor has always been its interface. Version 3.4 retains the "retro-utility" aesthetic—clean, functional, and devoid of unnecessary bloatware. It presents the data as it is: clean lines, clear text, and no distracting animations.
The main dashboard displays:
The jump to version 3.4 introduced several enhancements that set it apart from earlier versions or generic COM sniffers. Here are the standout capabilities:
A factory automation engineer notices intermittent communication failures on an RS-485 network running Modbus RTU. By attaching Serial Bandwidth Monitor 3.4 to the master port, they observe that the poll/response cycle suddenly spikes to 100% bandwidth utilization every 30 seconds. This reveals a rogue slave device flooding the line – something a protocol analyzer might miss. Serial bandwidth monitor 3.4
Q: The tool shows zero activity even though data is flowing.
A: The serial filter driver may not be loaded. Reinstall the software with antivirus temporarily disabled. Then run sc query sbmfilter in an admin command prompt to verify.
Q: High CPU usage (above 10% on modern CPU). A: Reduce the sampling interval to 500ms or disable the live graph by switching to "Table View". Also, ensure you are not logging raw data to disk unnecessarily. A marine navigation system integrates a GPS receiver
Q: Unable to monitor USB-to-serial adapters. A: Version 3.4 supports standard FTDI, Prolific, and Silicon Labs chips. Install the latest VCP drivers from the chip manufacturer first, then restart the monitor.
Q: False bandwidth alerts due to interrupt storms. A: Increase the "Debounce" setting in Advanced > Alert Hysteresis to 5 consecutive samples before triggering. This data justifies switching to a multi-constellation GNSS
Version 3.4 typically supports raw data capture. It measures the bandwidth of the entire stream, including overhead bits (start, stop, and parity bits), providing a "wire speed" measurement rather than just application-layer speed.