Home / Shop / All products / StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction
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StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction

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Add an RS-232 serial null modem port to a laptop or desktop computer using an available USB-A port Add support for RS-232 DCE serial communication to your desktop or laptop computer and resolve DCE/DTE conflicts directly without the...

CHF 66.19 incl. VAT
Delivery time: 3–5 working days
Purchase options: PixelSummit Recommendation

  • Fast delivery from a Swiss warehouse
  • 3-year warranty
  • Personal support
  • Twint
  • HeyLight
  • Visa
  • Mastercard
  • Apple Pay
  • Invoice (CH)

Product information


Add an RS-232 serial null modem port to a laptop or desktop computer using an available USB-A port

Add support for RS-232 DCE serial communication to your desktop or laptop computer and resolve DCE/DTE conflicts directly without the need for additional crossed serial cables or adapters.

Serial Expansion

The 3m USB Null Modem Adapter adds an RS-232 DB/DE-9 (female) serial port to a desktop or laptop computer via a USB Type-A port. Secure the adapter to a serial device using the pre-installed, removable, slotted D-sub thumb screws, or install the included DB-9 nuts to ensure compatibility with other serial devices or cables.

LED Indicators

The data transmit and data receive LED indicators on the adapter enable real-time monitoring of connection activity. The USB LED indicates if the adapter has successfully connected to the desktop or laptop computer. All LEDs assist with diagnostics and troubleshooting.

Seamless Connectivity

The adapter is compatible with Windows, macOS, ChromeOS, and Linux. Drivers for Windows 7 and newer versions, macOS 10.15 and newer, and Linux are installed automatically. The USB to RS-232 adapter features a COM retention function that automatically reassigns the COM port value if the cable is disconnected and reconnected, or if the system is restarted.

Built for Durability

The robust TPE construction and Level 4 ESD protection (15kV air and 8kV contact) increase the reliability and longevity of the USB serial adapter. Copper shielding minimizes electromagnetic and radio frequency interference (EMI and RFI). Gold-plated connectors improve signal conductivity.

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About this product

StarTech.com 3m USB Null Modem Serial Adapter Cable, USB-A to DB9 RS232, FTDI, COM Retention, LED, Replaceable DB9 Screws & Nuts, Level-4 ESD Protection, Windows, macOS, ChromeOS and Linux - Rugged TPE Construction

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Frequently Asked Questions

What are the shipping costs and how long does delivery take?
Standard shipping CHF 8.90 (B-Post, 3–5 business days) or Express CHF 23.50 (Swiss-Express "Mond", 1–2 business days) – Delivery by Swiss Post, within Switzerland only. In-stock products are usually processed within one business day; out-of-stock components are procured within 2–3 business days. Pick-up in Winterthur is free of charge.
Can I also pick up my order?
Yes – free of charge at Sulzerallee 80, 8404 Winterthur, during our opening hours. Please wait for our pick-up confirmation before coming by.
How long is my warranty?
You receive a 3-year warranty on all products purchased from us, starting from the date of delivery. For repair work carried out by us and newly installed spare parts, we provide a 2-year warranty. Report any warranty claims to info@pixelgipfel.ch before returning the item and wait for RMA confirmation.
Can I return a product?
Yes – as a private customer with a delivery address in Switzerland, you have a voluntary right of return for 14 days from receipt: 100% for unopened items, 90% for opened but unused items, and under 85% refund for used items. Excluded are custom builds, personalized products, activated software and license keys, as well as opened products that come into contact with the body (e.g., headphones, headsets, VR glasses). Please register your return in advance at info@pixelgipfel.ch – the refund will be processed within 10 business days after inspection.
What payment methods do you accept?
TWINT, common credit and debit cards, and purchase on account with partial payment option via our partner Heylight. All prices include 8.1% VAT; shipping costs will be displayed in the checkout before the order is completed.
How long does it take to assemble my custom PC?
Once all components are available, assembly, configuration, and functional testing usually take 1–2 business days. If parts are not in stock, an additional 2–3 business days for procurement will apply; for pre-orders or special procurements, it can take up to 30 days – we will inform you of any delays.
Can I cancel my order?
You can usually cancel standard products that have not yet been shipped free of charge – please contact us at info@pixelgipfel.ch. For custom builds and specially ordered products, cancellations depend on the processing status; compensation of up to 20% may be charged for work already carried out and components already ordered.