SerialRUN User Guide

Quick Start

Connect your serial device to the computer via USB
Click the refresh button ↻ in the left panel to detect ports
Select a serial port from the dropdown (e.g., COM3)
Set the baud rate (default 115200, supports custom values)
Click the green Connect button
Type commands in the bottom terminal input box and click Send

Tip: If you don't know the baud rate, click the Auto button to auto-detect (progress shown in status bar).

Interface Layout

Top Toolbar

15 function buttons. Click to open/close the corresponding window:

Button	Function	Description
`Log`	Log Viewer	Send/receive records, export to CSV, auto-persisted
`Chart`	Data Chart	Real-time data rate curve
`PLC`	PLC Controller	Siemens, Mitsubishi, Delta, Omron presets
`Mod`	Modbus Debug	Quick register read/write, 8 function codes
`TCP`	TCP/RTU Bridge	Bridge Modbus TCP to serial RTU
`HMI`	HMI Simulator	Virtual Modbus slave (TCP/RTU)
`FT`	File Transfer	XMODEM/YMODEM/ZMODEM
`FB`	Frame Builder	Manual Modbus frame construction
`CAN`	CAN Bus	SLCAN frame capture and analysis
`I2C`	I2C/SPI	Scan and read/write I2C/SPI devices
`Scope`	Oscilloscope	Real-time waveform display
`Flash`	Flasher	STM32/ESP32 firmware flashing

Note: All panels are independent OS windows — drag, resize, and arrange freely. Child windows always stay on top.

Left Panel

Serial Port — Select port from dropdown, click ↻ to refresh
Baud Rate — Type custom value or click for common rates (300-921600)
Auto — Auto-detect baud rate (progress in status bar)
Port Config — Data bits, stop bits, parity, flow control
MCP Server — Enable/configure AI integration server
Record/Replay — Record and replay serial operations

Bottom Status Bar

Connection — Current port and baud rate
Data Stats — RX/TX byte counters and real-time rate
Recording — Red ● Recording indicator
AI Connection — Yellow MCP connection indicator

Terminal Features

The terminal displays all send/receive data with color-coded directions:

Green ↓ RX — Received data
Blue ↑ TX — Sent data
Yellow ⚙ SYS — System messages

Toolbar Controls

Timestamp — Show time before each message
Auto Scroll — Auto-scroll to latest message
CRC — Auto-append checksum on send
DTR/RTS — Control serial signals (when connected)
Auto Send — Repeat send at set interval
T/O — RX timeout (auto or manual)

Auto-Wrapping: The toolbar uses adaptive layout — controls automatically wrap when the window is narrow.

HEX Mode

Switch between TXT and HEX mode in the input box. HEX mode auto-strips spaces and 0x prefixes.

RX Timeout (T/O)

Controls how long to wait for more data after initial read:

Auto — Calculated by baud rate (check T/O checkbox)
Manual — Set custom value 10-2000ms (uncheck T/O)

Right-Click Menu

Copy — Copy current line
Copy All — Copy all terminal data
Convert to HEX — Show text as hex
Resend — Re-send the line data (TX only)

Modbus Debug

Quick register read/write with 8 function codes and configurable response timeout.

Quick Request

Set Slave ID (0-247), function code, start address
For reads: set quantity; for writes: set value
Response Timeout — 50-5000ms, default 500ms
TX/RX data also shown in terminal panel

Function Codes

Code	Name	Type
01	Read Coils	Read
02	Read Discrete Inputs	Read
03	Read Holding Registers	Read
04	Read Input Registers	Read
05	Write Single Coil	Write
06	Write Single Register	Write
15	Write Multiple Coils	Write
16	Write Multiple Registers	Write

Register Monitor

Set poll interval (100-10000ms) and view register values in real-time with address, raw value, and formatted display.

PLC Control

Professional PLC monitoring with brand presets and batch register operations.

Brands: Siemens S7-1200, Mitsubishi FX3U, Delta DVP, Omron CP1H, Custom
Data Types: BOOL, UINT16, INT16, UINT32, FLOAT32
Batch Read: Contiguous registers merged into single Modbus request
Inline Write: Click register row to edit and write values
Status Dots: Green/yellow/red = fresh (<3s) / aging (<10s) / stale

TCP/RTU Bridge

Bridge Modbus TCP clients to serial RTU devices. External SCADA/HMI software can communicate with serial devices via TCP.

Set TCP listen port (default 502)
Select serial port and baud rate
Set response timeout
Click Start to activate the bridge

MCP Server (AI Integration)

Built-in MCP server allows AI assistants to remotely control serial devices via TCP.

Setup

In left panel, find MCP Server
Check Enable MCP Server
Set port (default 9527) and bind address
Click Copy MCP Info to share with AI assistant

Available Tools (15)

Tool	Description
`list_ports`	List available serial ports
`connect`	Connect to serial port
`disconnect`	Disconnect from current connection
`send`	Send data (text or hex)
`read`	Read data from RX buffer
`send_command`	Send command and wait for response
`modbus_read`	Read Modbus RTU registers
`modbus_write`	Write Modbus RTU register
`plc_read`	Read PLC preset registers
`plc_write`	Write to PLC register
`status`	View connection status
`get_config`	Read UI settings
`set_config`	Update UI setting
`get_access_log`	View access log
`get_device_info`	Get device identification

Warning: LAN mode allows network access to your serial ports. Use with caution.

Tips & Troubleshooting

Tips

Start with 115200 baud rate for new devices
Use Auto button if you don't know the baud rate
HEX mode auto-strips spaces and 0x prefixes
Append CRC checksums for data integrity
Use Record/Replay for repeated test sequences
All data auto-saves to ~/.serialrun/ directory

FAQ

Question	Answer
Port list empty?	Click refresh. Check device connection and drivers. Linux: `sudo usermod -a -G dialout $USER`
No data received?	Check baud rate matches device, verify TX/RX wiring, check flow control.
Auto baud detection fails?	Ensure device is sending data during detection.
Modbus no response?	Check slave address, function code, address range, and CRC.
File transfer fails?	Ensure both sides use same protocol, try lower baud rate.

Data Persistence

File	Content
`config.toml`	Theme, language, baud rate settings
`logs.json`	Application logs (max 2000)
`terminal.json`	Terminal history (max 5000)
`warnings.json`	Warning/error history (max 1000)
`mcp_access_log.json`	MCP access log (max 1000)

User Guide

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