The PCM-3641 is a PC/104-compatible module with four individually configurable RS-232 ports. It works with PC/104 CPU modules to extend additional RS-232 ports. The PCM-3641 also features lots of functions such as high transmission speed 460 kbps; independent/shared IRQ and more. It also provides high-performance 16C554 UART communication chip with 16-byte FIFO to reduce CPU load. This makes the PCM-3641 especially suitable for multitasking environments.