Few new computers come with a serial port. Without the DB9-style connector, there’s no easy way to hook up older hardware that uses the RS-232/422/485 standards. And even when the port is present, it’s only possible to connect a single serial instrument.
A multi-port serial interface card overcomes these problems. Easily installed in a spare interface slot in the PC, these cards can accept connections from up to 16 separate serial devices. This way data acquisition or automation hardware is managed from a single location. Westward Sales carries serial interface cards for both the PCI Express slots found in new PCs and the older PCI bus. These come with a CD containing utilities and drivers for both Windows and Linux.
The serial interface card must be matched to the bus in the PC. Older computers use PCI, of which there were two versions. Version 1 is distinguished by a single notch in the interface card. It used 5V signaling. The later Version 2 used 3.3V. A Universal PCI card works with both versions and is identified by two notches.
PCI Express cards are not interchangeable with PCI. These use multi-lane technology to achieve much higher speeds than PCI can deliver. Lanes are designated as “x1, “x4,” “x8,” “x16,” and “x32.”
PCI interface cards are produced in both low profile and standard or full height formats. In a low profile card, the bracket securing the card in the case measures 79.2mm while that on a full-height card is 120 mm. Always purchase the right height card for the destination PC.
Westward sells serial interface cards made by Antaira Technologies that carry a 5-year warranty. These are available in both low profile and full height formats, for RS-232 and RS-422/485 formats separately, and also for RS-232/422/485 combined.
Full height two-port cards provide two DB9-style connectors. The MSC-102A and MSC-202A-V2 are RS232 examples for PCI and PCI Express respectively. The low profile versions of these cards, the MSC-102AL-1 and the MSC-202AL1, use a single connection cable splitting into two DB9 connectors.
Four port cards have a single DB44 connector and come with a cable breaking out to four DB9's. In an eight-port card, the cable breaks out to eight separate DB9's. A full-height 16 port card like the MSC-116A (PCI) or the MSC-216A (PCI Express) has two VHDCI-68 front panel connectors, each of which accepts a cable breaking out to eight DB9 connectors.
Serial devices are used in many industries, but serial ports are rare on new computers, and multiple ports unheard of. Connecting older serial equipment to a new PC is possible by installing a serial interface card. These are available in full height and low profile formats and for both RS-232 and RS-422/485. For more information contact a Westward Sales product specialist.