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Black metal box with four DB9 ports, LED lights, DIN rail and wall brackets

GearMo

GearMo GM-FTDI4X-M 4-Port USB 2.0 to RS-232 Serial Adapter

SKU CH-4VNB-DFNVR

Adds four DB9 serial ports over a single USB 2.0 link with FTDI chipset, COM retention, RX/TX LEDs, DIN-rail and wall brackets, and 9–48 V variable-voltage input in a rugged metal chassis

  • Adapter typeUSB to DB9 (RS-232)
  • Product colorBlack
  • Four serial ports from one USB 2.0 connection
  • FTDI chipset keeps COM ports after reboot
  • LED lights show power, RX and TX activity
  • Mount on DIN rail, wall or surface
  • Rugged metal case with 9 to 48 VDC input

Industrial four-port serial adapter

The GearMo GM-FTDI4X-M adds four DB9 RS-232 ports to a computer through a single USB 2.0 connection. It targets engineers, technicians and system integrators who need to link legacy serial equipment such as PLCs, meters or industrial machinery to modern laptops or desktops. A rugged metal chassis and included DIN-rail or wall-mount brackets suit cabinet and field installations.

FTDI chipset with COM retention

The adapter uses an FTDI chipset that preserves COM-port numbers across reboots and device reconnection. This behaviour prevents software from losing its assigned port, which is critical for automation scripts, SCADA systems and laboratory instruments that hard-code specific COM identifiers.

Self-powered or 9–48 VDC input

In default self-powered mode the unit draws all current from the host USB port, adding no external wiring. An optional powered mode accepts a 9–48 VDC supply for applications that require galvanic isolation or must keep serial ports active when the host is off. Power, RX and TX LEDs on each port give immediate visual status without extra test gear.

How it compares

Measured against everything we stock in USB Adapter Cables & Dongles, at today’s prices. Recalculated every night.

Price $71.99
Pricier than about 91% of the 1,430 comparable items (median $14.99).

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Specifications

Product
Brand nameGearmo
Model nameGM-FTDI4X-M
Product colorBlack
Adapter typeUSB to DB9 (RS-232)

Questions about this item

How do the four DB9 ports appear to the operating system once the adapter is installed?

Each port enumerates as an independent COM port that can be configured individually in Device Manager.

What does the USB 2.0 connection limit in real-world use?

The USB 2.0 link caps aggregate throughput at the bus maximum, so total serial traffic across all four ports cannot exceed that bandwidth.

What mounting options come in the box for a DIN rail or wall?

Both a DIN-rail clip and surface-mount brackets are included, letting you secure the metal chassis to a rail or flat surface.

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