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Green circuit board with gold edge connector and sixteen DB9 ports along the rear bracket

STARTECH

STARTECH PEX16S550LP 16-port low-profile serial expansion card

SKU CH-3JXY-C74EX MPN PEX16S550LP

Adds sixteen RS-232 serial ports via one PCIe slot with 921.6 Kbps throughput

  • TypePCI Express
  • External Ports16 x DB-9 (9 pin, D-Sub) Male
  • Internal Ports1 x SP4 (4 pin, Small Drive Power) Male
  • Operating Systems SupportedWindows 7, 8, 8.1, 10 Windows Server 2003, 2008 R2, 2012, 20
  • SpecificationsCard Type: Low Profile (SP bracket incl.) Chipset ID: ASMedi
  • Features16 DB9 RS232 ports from a single PCIe slot Enables high-spee
  • Adds 16 serial ports through one PCIe slot using 16 DB9 connectors
  • Reaches 921.6 Kbps per port for fast RS232 communication
  • Fits low-profile and full-profile systems with included SP bracket
  • Works with Windows 7 through 10 plus Server 2003 to 2016 and Linux 2.6x to 4.2x LTS
  • Provides +/-15kV ESD protection and selectable 5V or 12V power on pin 9

16-port low-profile serial card

The StarTech PEX16S550LP adds sixteen DB-9 RS-232 ports through a single PCI Express slot. It targets industrial integrators, legacy equipment maintainers and server administrators who need many serial connections in a compact form factor. The low-profile design fits both slim and standard chassis without modification.

Passive cooling and minimal power draw

The card operates without a fan, relying on the host system airflow for thermal management. It draws auxiliary power through an internal SP4 connector with selectable 5 V or 12 V output on pin 9, keeping total consumption low. ESD protection rated at ±15 kV helps maintain signal integrity in electrically noisy environments.

Two breakout cables and a driver disc included

The package supplies two breakout cables that convert the on-board headers to the sixteen external DB-9 ports. A low-profile bracket is provided for slim chassis installations. The driver CD covers Windows 7 through 10, Windows Server 2003 through 2016 and Linux kernels 2.6 to 4.2 LTS, while a quick-start guide simplifies first-time setup.

Highlights

  • Adds 16 serial ports through one PCIe slot using 16 DB9 connectors
  • Reaches 921.6 Kbps per port for fast RS232 communication
  • Fits low-profile and full-profile systems with included SP bracket
  • Works with Windows 7 through 10 plus Server 2003 to 2016 and Linux 2.6x to 4.2x LTS
  • Provides +/-15kV ESD protection and selectable 5V or 12V power on pin 9

Specifications

BrandStarTech.com
ModelPEX16S550LP
TypePCI Express
External Ports16 x DB-9 (9 pin, D-Sub) Male
Internal Ports1 x SP4 (4 pin, Small Drive Power) Male
Operating Systems SupportedWindows 7, 8, 8.1, 10
Windows Server 2003, 2008 R2, 2012, 2012 R2, 2016
Linux 2.6x to 4.2x LTS Versions only
SpecificationsCard Type: Low Profile (SP bracket incl.)
Chipset ID:
ASMedia - ASM1083
SystemBase - SB4002A, SB16C1058
Industry Standards: PCI Express 1.1, PCI Power Management 1.2
Interface: Serial
Ports: 16
Data Bits: 5, 6, 7, 8
Max Baud Rate: 921.6 Kbps
Serial Protocol: RS-232
Stop Bits: 1, 1.5, 2
Features16 DB9 RS232 ports from a single PCIe slot
Enables high-speed serial communication with data transfer rates up to 921.6 Kbps
Compatible with low- and full-profile desktop computers or servers
Fully compliant with PCI Express 1.0a/1.1 specification, compatible with 1x, 2x, 4x, 8x, and 16x PCIe bus
+/-15kV ESD protection
Selectable power output (5V or 12V ) on pin 9 for the serial port
Data Bits: 5, 6, 7, or 8-bit characters
Windows and Linux support
Dimensions0.90" x 2.70" x 6.60"
Weight0.16 lbs.
Package Contents1 x serial card
1 x low-profile bracket
2 x breakout cables
1 x driver CD
1 x quick-start guide
Shipping weight0.23 kg
Package size290 × 190 × 70 mm

Questions about this item

How do I install the PEX16S550LP in a low-profile chassis and which bracket do I use?

Fit the included low-profile bracket to the card, insert it into any PCIe x1, x2, x4, x8 or x16 slot, then connect the two breakout cables to the on-board headers and secure the DB9 panel brackets to the case. The step often missed is attaching the SP4 power cable to the card's 4-pin connector so the ports can supply 5 V or 12 V on pin 9.

What maintenance or replacement will the PEX16S550LP need over time?

The card has no moving parts or user-serviceable components. Driver updates for newer Windows or Linux kernels are the only ongoing requirement; if a port fails the whole card is replaced.

What limit appears first when all 16 ports run at 921.6 Kbps continuously?

The PCI Express 1.1 x1 link caps aggregate throughput, so sustained full-speed traffic on every port will hit the bus bandwidth ceiling before the individual UARTs reach their maximum rate.

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