SIIG, Inc JJ-E40011-S6 4-port RS-232 PCIe 2.0 hub

Four Serial Ports Added via PCIe

The SIIG DP CyberSerial 4S PCIe card provides four RS-232 DB9 ports through a single PCI Express x1 slot. It targets users connecting legacy industrial, medical or point-of-sale equipment to modern desktop or server platforms. The ASIX AX99100 chipset handles the conversion and supports baud rates up to 921Kbps. No external power adapter is required for the serial ports themselves.

Dual-Profile Bracket and Flexible Power

A low-profile and a full-height bracket are both included so the card fits standard and compact chassis without extra hardware. Each DB9 connector can supply either 5 V or 12 V on pin 9, selectable per port, letting you power external devices directly from the slot. The board is TAA compliant for government procurement and uses a standard PCIe 2.0 x1 edge connector that seats in any compatible slot.

Bandwidth and Distance Limits

The PCIe 2.0 x1 link provides enough throughput for four simultaneous serial streams at the rated speed, but aggregate traffic above that ceiling will queue. RS-232 signalling remains limited to short cable runs, typically under fifteen metres, and is not suited for long-distance or electrically noisy environments without additional isolation. Buyers needing more than four ports or galvanic isolation must look elsewhere.