The SIO4-104 family of boards can manage up to four ports. These boards support RS-232 and RS-422/485 interfaces through a single 40-pin header. A range of terminal block adapters is offered. The SIO4-104 boards ship with the SeaCOM suite of Windows 98/ME/NT/2000/XP drivers. There's also support for Linux, QNX, and DOS. Prices begin at $179. Extended temperature-range models (−40°C to 85°C) are available.
Sealevel Systems Inc.