Type II PCMCIA Card Provides Four RS-422/485 Serial Ports February 2000 Issue Published Date: February 01, 2000
Four fully independent serial ports can be added to a system with the QSP-200/300 Type II PCMCIA card, with each port configured as RS-485 by using a 60 ohm resistor or as RS-422 by connecting a 100 ohm resistors. Any combination of RS-422 and RS-485 ports can be used. The serial ports are implemented with 16550 UARTs providing 16-byte transmit and receive FIFOs, making the card suitable for use in multitasking environments. The RS-422/485 serial ports can be configured to operate in either full- or half-duplex mode and all ports can share a single interrupt. Supported under DOS, Windows 3.x, Windows 95/98 and OS/2, the card is said to be ideal for expanding any portable system. With RS-422 up to 10 devices can be configured on a single port; and up to 32 devices can be connected via a single port when using RS-485.
