The 7404e PCI Express serial interface provides four multifunction serial ports, each individually field-configurable for RS-232, RS-422, or RS-485. Each serial port utilizes a 16C954 UART with 128-byte Tx/Rx FIFOs that enables data rates to 921.6K bps for reliable high-speed communications in data intensive applications. This high-performance UART includes 9-bit framing support and is register compatible with legacy 16550 software applications. In addition, the board derives a 62.5 MHz clock from the PCI Express link. This ultra high speed clock is divided by a flexible 8-bit clock prescalar with 1/8 steps to provide support for the widest range of standard and non-standard baud rates.
In RS-485 mode the board provides automatic control of the RS-485 driver in hardware, eliminating the need for application software control. This allows the 7404e to be used with standard serial communications applications and removes the risk of bus contention and data corruption. Additionally, RS-485 network termination, critical to robust multi-drop communication, can be selectively added to the circuit via DIP-switches. In RS-232 mode, all modem control signals are implemented for maximum compatibility with a variety of serial peripherals.
software driver and utilities make installation and operation easy using Microsoft Windows and Linux operating systems.
The 7404e is a PCI Express X1 board compatible with any PCI Express slot. The board ships with a 36 inch cable (Item# CA143) that terminates to four DB9M connectors.