PCI Express card providing two opto isolated RS422/485 serial ports. Data transfer rates up to 921,600 baud rates and the 128 byte deep transmitand 128 byte receive FIFOS, coupled with 1 Mbit/s line drivers deliver uncompromising performance on your PC. Optical isolation provides greater protection from electrical current surges to both the card itself and the PC. It improves noise immunity by isolating the PC from the card's transmit ground.