QUATECH has released one, two and four port RS422/485 serial low profile boards, now available from Interworld Electronics. The SSCLP-200/300 provides one, DSCLP-200/300 provides two and QSCLP-200/300 provides four independent serial ports to a host computer via a single low profile PCI slot.
The boards are built using the smallest (MD1) low profile board specification, which allows them to be used in even the smallest sized systems.
Low profile PCI was designed to provide greater flexibility for embedded systems, thin-clients, desktop and server environments. The boards are mechanically similar to standard PCI boards, but use a shorter board and a different mounting bracket.
The boards are built on 32-bit addressing, and can be used in standard PCI backplanes or with specialised low profile PCI brackets.
Each port on the board can be configured as either RS422 or RS485 by using Quatech’s auto-toggle feature. Full-duplex, manual half-duplex and auto-toggling half-duplex options are available. In half-duplex mode the S-422/485 transmitter can be enabled and disabled via the RTS or DTR signals (controlled through the modem control register on the UART) or with the new auto-toggle feature, which only drives the lines when transmitting data.
The channels are addressed in continuous I/O blocks (32 byte for the four port board and 16-byte for the two port board, and 8-byte for the one port board) for simplified software access. And all channels may also share one PCI interrupt.
An interrupt status register is available for determining the interrupt source.
The boards are implemented with 16550 UARTs (DSCLP/SSCLP) or 16554 UARTs (QSCLP) both containing 16-byte FIFOs. They have a clock-multiplying feature allowing them to achieve data rates as high as 921.6 kbps (460.8 kbps for DSCLP/SSCLP).
The high clock speeds and deep FIFOs will greatly reduce CPU overhead, making these boards an ideal choice for heavy multi-tasking environments.
The SSCLP-200/300 uses a single on-board D9 serial port. The DSCLP-200/300 and QSCLP-200/300 each come with a cable providing respectively two or four D9 ports. Windows 95/98/Me/NT/2000 and OS/2 are supported. Interworld Electronics 03 9563 5011.