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Serial Port Utility 6.6.2

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Release highlights

What is new in 6.6.2

Current

These release notes apply to every platform build. Download details stay in the platform picker.

Features

  • X/YMODEM file transfer: Send and receive files over an established serial, TCP or RFC 2217 connection with XMODEM, XMODEM-CRC, XMODEM-1K, YMODEM and YMODEM-G. Protocol traffic is isolated from ordinary terminal data, while a non-modal progress bar reports the file, progress, rate, ETA and retry count. TCP servers can pin a selected client, so remote firmware updates no longer require another terminal application
  • Single-connection RFC 2217 remote serial: RFC 2217 is now available directly in the port list for connecting to Moxa NPort, ser2net or another Serial Port Utility and setting remote baud rate, data bits, parity, stop bits, flow control and DTR/RTS in the same connection. The device server's existing configuration is preserved by default; parameters are sent only after the user explicitly takes control. Peers without RFC 2217 support warn and degrade safely
  • RFC 2217 bridge client mode: A bridge can dial a device server and synchronize its serial parameters from the link's other endpoint. Parameters are sent once negotiation succeeds and only changes are sent afterward; remote replies are recorded in the link messages but never applied back to the local serial port
  • Remote control-line status: RFC 2217 connections show the remote CTS, DSR, RI and DCD states, making hardware handshaking behind a device server directly observable

Fixes

  • RFC 2217 negotiation: The access server now answers a client's WILL with DO. It previously worked only with clients that also send DO, such as pyserial; a client that opens with WILL alone waited until it timed out and fell back to a plain socket
  • RFC 2217 negotiation no longer ping-pongs: Answers are tracked per option and sent only when they change something. Two Serial Port Utility bridges pointed at each other used to exchange WILL/DO forever
  • RFC 2217 compatibility: COM-PORT-OPTION refusals are now interpreted by role, fixing parameter delivery after negotiation with ser2net
  • Terminal passthrough on network connections: Fixed keyboard passthrough checking only the local serial handle, which made typing ineffective on TCP, UDP and RFC 2217 connections
  • Bridge peer events: A peer arriving on the device end no longer opens a negotiation with the network end
Version archive

Previous releases

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6.6.0

File
SerialPortUtility-v6.6.0.dmg
File size
38.8 MB
SHA-256
3bb23798605390676cec2562d6008d1ec891e16cb17c83d8d09a4e5914099f95

6.6.0 (2026-07-19)

中文版

新特性
  • 连接活动指示灯: 连接组新增可交互的 TX/RX 与控制线指示灯，实时闪烁反映收发与控制线状态；退役旧版控制线界面，改用指示灯呈现
  • 串口控制线: 新增串口控制线处理，设置对话框新增 Control Lines 标签页
  • Modbus 请求构建器: 工具菜单新增 Modbus 请求构建器
  • 逐项快捷设置: 所有分组均支持逐项快捷设置，快捷设置选择器移入设置对话框
  • 行结束符下拉框: 以 Line Ending 下拉框替代发送区的自动换行复选框
  • 恢复上次连接: 启动时自动恢复上次退出时打开的连接
  • 终端光标与真实发送统计: 终端模式新增光标显示，发送计数改为真实统计
界面改进
  • TCP/UDP 模式界面: 静默服务器错误弹窗，优化 TCP/UDP 模式界面
  • 工具栏: 重做日志记录与快捷设置的工具栏控件
  • 多处 UI 对齐与打磨: 统一接收 Auto FL 与发送 Loop 行、对齐 Line Ending 与 Append Checksum 下拉框等
修复与完善
  • 设置默认值: 补齐并保护设置面板中 Log/Display 相关默认值，不再保存空的 Rx/Tx 时间格式
  • .spu 会话加载: 以 toBool 解析 .spu 布尔标记，确保已保存的 true 值在重载后保留
  • 国际化: 中文界面将格式单选项标注为 Text 而非 ASCII
  • 日志目录: 打开日志文件前先创建日志目录

English

Features
  • Connection activity lamps: The connection group gains interactive TX/RX and control-line indicator lamps that blink to reflect live traffic and control-line state; the classic control-line UI is retired in favour of the lamps
  • Serial control lines: Added serial control line handling with a new Control Lines tab in the settings dialog
  • Modbus request builder: Added a Modbus request builder to the Tools menu
  • Per-field quick settings: Quick settings are now available per field across all groups, with the picker moved into the settings dialog
  • Line Ending combo: Replaced the send auto-feed checkbox with a Line Ending combo
  • Restore last connection: Automatically restores the connection that was open at last exit
  • Terminal caret & honest Tx metrics: The terminal mode shows a caret and reports real Tx counts
UI Improvements
  • TCP/UDP mode UI: Silenced the server-error popup and polished the TCP/UDP mode UI
  • Toolbar: Reworked the log-recording and quick-settings toolbar controls
  • UI alignment & polish: Unified the receive Auto FL and send Loop rows, aligned the Line Ending and Append Checksum combos, and more
Fixes & Enhancements
  • Settings defaults: Seeded and guarded the remaining Log/Display defaults in the settings panel; never store empty Rx/Tx time formats
  • .spu session loading: Parse .spu bool flags with toBool so saved true values survive reload
  • Internationalization: Label the format radios Text, not ASCII, in Chinese
  • Log directory: Create the log directory before opening the log file
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3.9.1

File
SerialPortUtility_391.dmg
  • Fixed the setting file save problem
  • Updated support to multi port
  • Add checkable menu for auto restore last connection
  • Improved support for 4K and retina screen
Download this version Release details