Small, precise communication tools for testing hardware
Serial (COM), Modbus, TCP, UDP, a device simulator, a network device finder, an SCPI instrument terminal and a live plotter — one small program per job. Free and open source (GPL-3.0), Windows 10 and 11.
- No ads
- No bundles
- Installer or portable
- Open source
PortDock tools
PortDock Serial
Serial (COM) terminal with signal lines and auto-reconnect
Details →PortDock Modbus Slave
Modbus slave simulator (RTU and TCP) with register tables and fault injection
Details →PortDock TCP
TCP client, server and relay with multiple peers, echo and auto-reconnect
Details →PortDock UDP
UDP sender/receiver with broadcast, multicast and echo
Details →PortDock Simulator
Rule-based fake device over serial, TCP and UDP
Details →PortDock Net Scan
Find devices on industrial networks — industrial ports, long-term ping
Details →PortDock Modbus Master
Modbus RTU/TCP master (poll tool) — typed values, writes, Slave ID scan
Details →PortDock SCPI
SCPI instrument terminal — LAN socket and RS-232, no VISA
Details →PortDock Plot
Live graphs of numbers from serial, TCP and UDP
Details →Why PortDock
It reconnects
Unplug and replug a USB adapter: PortDock finds the same device again and logs when it dropped.
One line, one message
Idle gap, terminator, fixed length or Modbus RTU framing — no more merged or split data.
See before you send
The exact bytes that will go out, including checksum and line ending, are shown as you type.
Korean and English
Screens, errors and help in both languages, with tooltips on every control.
Guides and device register maps
Reading Modbus RTU frames — request, response, exception, CRC
Read →USB-serial adapter latency — why frames split and replies arrive late
Read →RS-485 wiring checks — five things to look at when replies are missing or garbled
Read →No reply from a Modbus device — a checklist for RTU and TCP
Read →Modbus addresses: 0-based vs 40001 notation — from manual to wire
Read →Modbus register maps for 10 Korean devices
Inverters, temperature controllers, power meters — sources, JSON
Details →Need PC software for your devices?
Serial and Ethernet device integration, test and measurement software, and maintenance or migration of legacy programs.