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

Part: 7404   Model: COMM+4.PCI

(2 customer reviews)


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The 7404 PCI serial interface provides four field selectable ports configurable as RS-232, RS-422, or RS-485 supporting asynchronous data rates up to 460.8K bps. In RS-485 mode, our auto-enable feature allows the 7404 to be viewed by the operating system as a standard COM port. The 7404 is Universal Bus (3.3V and 5V) compatible and can be installed in a standard height PCI slot. The included 36-inch cable terminates to four DB9 Male connectors.


Additional information

Communications Chip


Electrical Interface

RS-232, RS-422, RS-485

Humidity Range

10 – 90% Relative Humidity, Non-Condensing

Host Interface(s)


Max Data Distance

4000 feet

Max Data Rate

460.8K bps

Operating Temperature

0°C to 70°C (32°F to 158°F)

PC Bracket

Standard Height

# of Ports


RoHS Compliant


Serial Connector(s)


Storage Temperature

-50°C to 105°C (-58°F to 221°F)

UART Series

850 UART

  • Compliant with RoHS and WEEE directives
  • Each port individually configurable for RS-232, RS-422, or RS-485
  • 16C864 buffered UART with 128-byte FIFOs
  • Data rates to 460.8K bps
  • Automatic RS-485 enable/disable
  • Universal Bus (3.3V and 5V) compatible
  • Included 36″ cable terminates to four DB9 Male connectors (Item# CA143)

Windows Software

Software: SeaCOM - Windows

Linux Software

Software: SeaCOM - Linux


Manual: 7404

2 reviews for COMM+4.PCI

  1. Jon

    Rock Solid Communications
    The 7404 fits the bill for an easy to configure multiport card that is easily configured to communicate with RS232 and RS485 devices. It is very well supported by Sealevel engineers and has a lifetime warranty!

  2. Carlos

    Great product!
    We currently are using several Sealevel PCI RS-232/422/485 (PN# 7404) boards in our testing department. Our experience using these cards has always been satisfactory. The cards install easily and perform excellent!
    We normally use then in the RS-422 configuration but we like the flexibility to configure each port to either RS-232 or RS-422 if needed.
    We would definitely recommend this card. Our experience when contacting Sealevel has also been excellent.

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