Release v6.6.2 · alithon/serial-port-utility

6.6.2 (2026-08-05)

X/YMODEM 文件传输: 在已建立的串口、TCP 或 RFC 2217 连接上直接收发文件，支持 XMODEM、XMODEM-CRC、XMODEM-1K、YMODEM 与 YMODEM-G。传输期间协议数据与普通终端数据隔离，非模态进度条实时显示文件名、进度、速率、剩余时间与重传次数；TCP 服务端可锁定指定客户端，远程固件升级无需再切换到其他终端工具
单连接 RFC 2217 远程串口: 端口列表新增 RFC 2217 模式，可直接连接 Moxa NPort、ser2net 或另一台 SPU，并在同一连接中设置远端波特率、数据位、校验、停止位、流控和 DTR/RTS。默认保留设备服务器自身配置，只有用户明确接管后才下发参数；不支持 RFC 2217 的对端会给出警告并安全退化
RFC 2217 桥接客户端模式: 桥接可主动连接设备服务器，并把链路另一端的串口参数同步到远端串口；协商成功后一次性下发，之后只补发变化项，远端回执会记录在链路消息中但不会反向修改本机串口
远程控制线状态: RFC 2217 连接可显示远端 CTS、DSR、RI 与 DCD 状态，让设备服务器后的串口握手状态也能直接观察

RFC 2217 协商: 服务端现在会用 DO 回应客户端的 WILL——此前只对同时发送 DO 的客户端（如 pyserial）有效，只发 WILL 的客户端会一直等到超时并退化成普通 socket
RFC 2217 协商不再无限往复: 协商按选项记录状态，只有当回答会改变状态时才回复；此前两台互相对接的 SPU 会无休止地交换 WILL/DO
RFC 2217 兼容性: 按客户端与服务端角色分别处理 COM-PORT-OPTION 的拒绝响应，修复与 ser2net 协商后参数无法下发的问题
网络连接终端直通: 修复终端键盘直通仅检查本地串口句柄、导致 TCP、UDP 与 RFC 2217 连接中键盘输入无效的问题
桥接对端事件串台: 设备端出现新对端时不再向网络端发起协商

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

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

Platform	File
Windows 10 1809 or later, 64-bit	`serial_port_utility_*.exe`
macOS 12 or later, Apple Silicon	`SerialPortUtility-*.dmg`
Linux x86_64 (Ubuntu 22.04 or later)	`serial-port-utility-*-linux-x86_64.tar.gz`

First-launch notes for each platform — Gatekeeper on macOS, the runtime libraries on Linux —
are in the README.

SHA-256 checksums are published with every build at
alithon.com/downloads.