RS-232, RS-422, or RS-485? 3.3 V or 5 V? Isolated or nonisolated? How many ports? The MIport (Multi-Interface) line is a new series of universal PCI cards said to bring order to the chaotic world of serial communications.

Just choose the number of ports you need, select isolated or nonisolated, and you’re set. The rest is covered for you! The MIport universal serial cards suit both 3.3- and 5-V PCI bus signals and cover the three main serial protocols: RS-232, RS-422, and RS-485.

Traditionally, PCs have had 5-V buses. But newer PCs are beginning to ship with 3.3-V buses. The cards look similar, but they are electrically and physically incompatible. MIport serial cards solve this problem. They suit both 3.3- and 5-V buses to save inventory bins and selection errors.

Few serial cards in the past would accommodate more than one protocol. You chose RS-232 to add extra ports, RS-422 to extend range up to 4,000', or RS-485 if you needed both long range and multidrop capabilities. The new MIport line combines all three protocols in a single card.

You have to choose the number of ports and whether you need an isolated or nonisolated card. B&B recommends isolated cards for all communications distances longer than 50'.

Isolated serial cards are strongly suggested for any PCs connected to data lines that run near high-voltage power lines, radio transmitters, heavy duty motors, or other major power users that start and stop. These sources create spikes and surges in a data line, and if those rogue currents reach your PC, it could be toast.

Nonisolated cards are available for less threatening environments, such as offices and non-mission-critical PCs. They provide voltage and RS-232/422/485 universality at a lower cost. Prices start at $179.95.

B&B Electronics
www.bb-elec.com