7404e Board with Included DB37 Female to (4) DB9 Male Cable (Item# CA143)
7404e Board with Included DB37 Female to (4) DB9 Male Cable (Item# CA143)

Part# 7404e


PCI Express 4-Port RS-232, RS-422, RS-485 Serial Interface


Request a Quote | Where to Buy | Email Sales
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.

Sealevel SeaCOM 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.
Host Interface PCI Express
# of Ports 4
Electrical Interface RS-232, RS-422, RS-485
RoHS Yes
UART Series 950 UART
Serial Connector(s) DB9M
PC Bracket Standard Height
Communications Chip 16C954
Oscillator 62.5 MHz
Max Data Rate 921.6K bps
Max Data Distance 50 feet (RS-232), 4000 feet (RS-485)
Cable Connector DB9M (4)
Board Connector DB37M
Operating Temperature 0 - +70C
Storage Temperature -50 - +105C
Humidity Range 10 - 90% Relative Humidity, Non-Condensing
  • • Each port individually configurable for RS-232, RS-422, or RS-485
  • • 16C954 buffered UARTs with 128-byte FIFOs
  • • Oscillator and clock prescalar support wide range of baud rates
  • • Supports 9-bit protocol framing
  • • Each port supports data rates to 921.6K bps
  • • RS-485 line termination, pull-up and pull-down resistors for each port are selectable via dipswitch
  • • RS-485 ECHO can be enabled/disabled via dipswitch
  • • PCI Express X1 compliant
  • • Compatible with all standard size PCI Express slots
  • • All modem control signals implemented in RS-232 mode
  • • Automatic RS-485 enable/disable in hardware
  • • Included 36" cable terminates to four DB9M connectors (Item# CA143)

DB9 to DB25 Serial Cable
DB9 to DB25 Serial Cable


Terminal Block Kit
Terminal Block Kit


DB9 Serial Extension Cable
DB9 Serial Extension Cable


Terminal Block
Terminal Block


Terminal Block Kit
Terminal Block Kit


DB78 Extension Cable
DB78 Extension Cable


Modular Adapter
Modular Adapter


DB9 Cable with Tinned Leads
DB9 Cable with Tinned Leads


Terminal Block Kit
Terminal Block Kit


Proudly Made in the USA
© Copyright 1996 - 2015, Sealevel Systems, Inc. All rights reserved.