Brainboxes PCI 4 port OPTO RS422/485 interface cards/adapter UC-368

Universal PCI card providing 4 industry standard 9 pin
RS422/485 serial COM ports in a single PCI slot. Velocity
megabaud data transfer rates and 64 byte deep FIFO
guarantees uncompromising performance and fault-free use.
Optical isolation provides greater protection from electrical
current surges to both the card itself and the PC.
Universal PCI is fully compatible with both 3.3Volt and 5Volt PCI
slots; protecting your investment into the future.