Dual Channel RS-232 PCMCIA Card Two independent serial interfaces Configurable for RS-422 and RS-485 PCMCIA Card Services Specification 2.1 compliant Client software driver for DOS and OS/2 Windows 95/98 and Windows 2000 compatible 16550 UARTs with 16-byte FIFOs standard Selectable and shareable interrupts Selectable I/O base address
The DSP-200/300 adds two fully independent serial ports to a host PC. Each port can be configured as RS-485 by using a 60 ohm resistor, or as RS-422 by connecting an 100 ohm resistor. Any combination of RS-422 and RS-485 ports can be used. The DSP-200/300 serial ports are implemented with 16550 UARTs that provide 16-byte transmit and receive FIFOs, making the card ideal for use in multi-tasking environments. The RS-422/485 serial ports may be configured to operate in either Full-Duplex or Half-Duplex mode (but all ports must operate in the same mode). The default is Full-Duplex with the RS-422/485 output drivers enabled. Half Duplex mode may be selected via software configuration. (However, under Windows environments, only point to point communication is supported, not multi-drop networks and Half Duplex options.) In Half Duplex mode the RS-422/485 transmitter may be enabled and disabled via the RTS or DTR signals, both of which are controlled through the Modem Control Register on the UARTs. A RTS-CTS modem control handshake can be implemented.
The DSP-200/300's serial ports can be addressed in either Block Mode or COM Mode. In COM Mode the ports are configured at the standard COM I/O address locations. In Block Mode the two serial ports are configured in one 16-byte continuous block of I/O space. This block must begin on an even 16-byte boundary. Both ports can share one interrupt using an interrupt status register to indicate which port triggered the interrupt.
All necessary software is included to install and configure the DSP-200/300 for use with DOS/Windows 3.x, OS/2, Windows 95/98 and Windows 2000.