{"product_id":"hl-340-usb-to-rs232-serial-adapter-db9-ch340-windows-com-port","title":"HL-340 USB to RS232 Serial Adapter DB9 Cable | Windows 7\/8\/10\/11 64-bit | CH340 Chip | COM Port Converter","description":"\u003ch2\u003eHL-340 USB to RS232 Serial Adapter — DB9 Cable | CH340 Chip | Windows 7\/8\/10\/11 64-bit\u003c\/h2\u003e\n\n\u003cp\u003eAdd a hardware RS232 COM port to any modern laptop or desktop that lacks a serial port. The \u003cstrong\u003eHL-340 USB to RS232 adapter\u003c\/strong\u003e uses the CH340 USB-to-UART bridge chip to create a fully functional RS232 serial port accessible as a standard Windows COM port — compatible with all software that uses the Windows COM port API. The DB9 male connector mates directly with RS232 equipment without adapters. Essential for programming PLCs, configuring industrial equipment, communicating with GPS receivers, updating CNC machine firmware, and interfacing with any legacy RS232 device.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHL-340\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eUSB Chip\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCH340 (340 chip variant also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInterface\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSB Type-A (host) to DB9 Male (RS232)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSignal Standard\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRS232 (±12V signal levels)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBaud Rates\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e300 bps – 921,600 bps\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupply Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3.3V – 5V (USB powered)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOS Support\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eWindows 7\/8\/10\/11 (32-bit and 64-bit), Linux, macOS\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDriver\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCH340 driver (free download from WCH official website)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eConnector\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eDB9 Male (9-pin D-sub)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eMainland China\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eRS232 vs. USB — Why RS232 Still Matters\u003c\/h3\u003e\n\u003cp\u003eDespite USB replacing RS232 on consumer devices, RS232 remains the dominant serial interface in industrial, scientific, and legacy equipment because:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLong cable runs\u003c\/strong\u003e — RS232 supports cable lengths up to 15 metres (50 feet) at standard baud rates, far exceeding USB’s 5-metre limit\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNoise immunity\u003c\/strong\u003e — ±12V signal levels provide excellent noise immunity in industrial environments\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSimplicity\u003c\/strong\u003e — RS232 requires no enumeration, no drivers on the device side, and no protocol overhead\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLegacy installed base\u003c\/strong\u003e — millions of PLCs, CNC machines, test instruments, and industrial controllers use RS232 and will continue to do so\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eDB9 Pin Assignment (RS232)\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003ePin\u003c\/th\u003e\n\u003cth\u003eSignal\u003c\/th\u003e\n\u003cth\u003eDirection\u003c\/th\u003e\n\u003cth\u003eFunction\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003ctd\u003eDCD\u003c\/td\u003e\n\u003ctd\u003eIn\u003c\/td\u003e\n\u003ctd\u003eData Carrier Detect\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003ctd\u003eRXD\u003c\/td\u003e\n\u003ctd\u003eIn\u003c\/td\u003e\n\u003ctd\u003eReceive Data\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003ctd\u003eTXD\u003c\/td\u003e\n\u003ctd\u003eOut\u003c\/td\u003e\n\u003ctd\u003eTransmit Data\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003eDTR\u003c\/td\u003e\n\u003ctd\u003eOut\u003c\/td\u003e\n\u003ctd\u003eData Terminal Ready\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003ctd\u003eGND\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003ctd\u003eSignal Ground\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e6\u003c\/td\u003e\n\u003ctd\u003eDSR\u003c\/td\u003e\n\u003ctd\u003eIn\u003c\/td\u003e\n\u003ctd\u003eData Set Ready\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e7\u003c\/td\u003e\n\u003ctd\u003eRTS\u003c\/td\u003e\n\u003ctd\u003eOut\u003c\/td\u003e\n\u003ctd\u003eRequest to Send\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003ctd\u003eCTS\u003c\/td\u003e\n\u003ctd\u003eIn\u003c\/td\u003e\n\u003ctd\u003eClear to Send\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e9\u003c\/td\u003e\n\u003ctd\u003eRI\u003c\/td\u003e\n\u003ctd\u003eIn\u003c\/td\u003e\n\u003ctd\u003eRing Indicator\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eCH340 chip\u003c\/strong\u003e — reliable, widely supported USB-UART bridge with stable Windows 64-bit drivers\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eWindows 7\/8\/10\/11 64-bit support\u003c\/strong\u003e — works with all modern Windows versions including Windows 11\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eDB9 male connector\u003c\/strong\u003e — mates directly with RS232 equipment without gender changers\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFull RS232 signal support\u003c\/strong\u003e — TXD, RXD, RTS, CTS, DTR, DSR, DCD, RI — all signals available\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003e300–921,600 bps baud range\u003c\/strong\u003e — covers all standard industrial and consumer baud rates\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eUSB powered\u003c\/strong\u003e — no external power supply required\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eLinux and macOS compatible\u003c\/strong\u003e — CH340 drivers available for all major operating systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCommon Applications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003ePLC programming and configuration (Siemens, Mitsubishi, Omron, Allen-Bradley)\u003c\/li\u003e\n  \u003cli\u003eCNC machine firmware update and configuration\u003c\/li\u003e\n  \u003cli\u003eGPS receiver NMEA data reading\u003c\/li\u003e\n  \u003cli\u003eIndustrial instrument configuration (oscilloscopes, power supplies, analysers)\u003c\/li\u003e\n  \u003cli\u003eModem and router serial console access\u003c\/li\u003e\n  \u003cli\u003eBarcode scanner and POS terminal connection\u003c\/li\u003e\n  \u003cli\u003eLegacy computer and terminal emulation\u003c\/li\u003e\n  \u003cli\u003eArduino serial monitor via RS232 (with level converter)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eDriver Installation (Windows)\u003c\/h3\u003e\n\u003col\u003e\n  \u003cli\u003eDownload the CH340 driver from the WCH official website (wch.cn) or search “CH340 driver download”.\u003c\/li\u003e\n  \u003cli\u003eRun the installer and follow the prompts.\u003c\/li\u003e\n  \u003cli\u003ePlug in the USB adapter — Windows will assign a COM port number (e.g., COM3).\u003c\/li\u003e\n  \u003cli\u003eVerify the COM port in Device Manager under “Ports (COM \u0026amp; LPT)”.\u003c\/li\u003e\n  \u003cli\u003eConfigure your serial software (PuTTY, Tera Term, HyperTerminal) with the assigned COM port and correct baud rate.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Does this work with Windows 11?\u003c\/strong\u003e\u003cbr\u003eA: Yes. The CH340 driver supports Windows 11 (32-bit and 64-bit). Download the latest driver version from WCH for best compatibility.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can I use this to program an Arduino?\u003c\/strong\u003e\u003cbr\u003eA: The HL-340 provides an RS232 (DB9) output, not a TTL serial output. Arduino programming requires TTL-level serial (3.3V or 5V). Use a USB-to-TTL adapter (CH340G or CP2102 module) for Arduino programming instead.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What is the maximum cable length I can use with this adapter?\u003c\/strong\u003e\u003cbr\u003eA: RS232 supports cable lengths up to 15 metres (50 feet) at standard baud rates. At lower baud rates (9600 bps), longer cables may work reliably.\u003c\/p\u003e\n\n\u003ch3\u003ePackage Contents\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1× HL-340 USB to RS232 DB9 Serial Adapter Cable (chip variant as selected)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"340 chip","offer_id":46991417934059,"sku":"14:1202#340 chip","price":7.32,"currency_code":"USD","in_stock":true},{"title":"HL-340","offer_id":46991417966827,"sku":"14:350852#HL-340","price":8.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/hl340-usb-to-rs232-db9-adapter.webp?v=1761890341","url":"https:\/\/keszoox.com\/products\/hl-340-usb-to-rs232-serial-adapter-db9-ch340-windows-com-port","provider":"Keszoox","version":"1.0","type":"link"}