The BLS 2322S is a high-performance RS-232 card with 16C550-style UARTs that feature 16-byte transmit and receive buffers to help guard against loss of data in your busy system. The card may be addressed as COM1: to COM4: or any other I/O address you choose from 000 up to 3F8 hex. The backplate has two standard DB-9M connectors.
Both ports are capable of operating at speeds up to 460 kbaud simultaneously, making the card ideal for high-speed applications such as ISDN modems.
Interrupt Sharing: The Key to Adding Many Serial Ports
The powerful interrupt feature allows multiple ports on a single card to use the same interrupt. Any of eleven interrupt choices are available for each port. Unit is jumper-selectable for compatibility with protocols used by Digi®. This functionality provides drop-in replacement capability at reduced cost. Because each port's address may be defined individually, you don't have to worry about address conflicts the way you would with cards that use 32- and 64-byte blocks for addressing. Our serial cards are compatible with all application software that communicates with a standard serial port using an 8250 or 16C450 UART (the UARTs which virtually all PC's use for serial ports).
Drivers are automatically and instantly disabled (and receivers enabled) after transmission of the stop bit. Drivers and receivers may also be controlled with data bits 0 and 1 by writing to the base address+7 for the port (MetraByte COM-485 protocol compatible). RTS and CTS flow control is supported as well. Convenient on-board jumpers allow for 220-ohm termination as needed for each driver and receiver.