Serial Bandwidth Monitor 3.4 [2026]

Serial Bandwidth Monitor 3.4: Precision Monitoring for Critical Connections

In an era dominated by high-speed Ethernet and fiber optics, it is easy to forget the backbone of industrial automation, scientific instrumentation, and legacy networking: the serial port. From RS-232 to RS-485, these connections remain vital for controlling machinery, gathering data from sensors, and managing network infrastructure.

However, diagnosing bottlenecks in a serial connection has traditionally been a guessing game. Enter Serial Bandwidth Monitor 3.4, the latest iteration of the lightweight, precision tool designed to bring visibility to the invisible flow of data through your COM ports. Serial bandwidth monitor 3.4

1. Industrial PLC Debugging

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

Main UI elements

• Port list: shows all detected COM ports (physical and virtual).
• Throughput columns: RX (receive) B/s, TX (transmit) B/s, peak values.
• Error columns: framing, parity, overrun counts.
• Activity graph: per-port live line chart.
• Controls: Start/Stop monitoring, sample interval, port filter, export log, thresholds.

Key Features of Version 3.4

• Real-Time Throughput Graphs: Visualize incoming and outgoing data rates in bits per second (bps) or bytes per second.
• Per-Port Statistics: Monitor up to 256 serial ports simultaneously (including virtual COM ports from USB-to-serial adapters).
• Timestamped Logging: Record raw serial data with microsecond precision for post-mortem analysis.
• Non-Intrusive Mode: Acts as a passive listener – it does not block or alter the data stream, making it safe for live systems.
• Bandwidth Alerts: Set custom thresholds to receive visual or audio alerts when data flow exceeds or drops below expected ranges.
• Protocol-Agnostic: Works with Modbus, Profibus, proprietary ASCII, binary protocols, and even raw TTL levels.