The MARC™ MULTII-PORT™ module is based on a powerful microprocessor that allows Intelligent processing of messages rather than just simply multiplexing them. All incoming messages received at the "Advantage Ports" are processed, as required, utilizing the selected protocol and presented to the "shared port" on a first come, first serve basis. If two or more messages arrive at the same time, they are serviced one at a time in a "round robin" process. Messages are not lost or garbled. Model 366-10P MULTII-PORT™ port multiplier increases a single serial port to two, three or four ports. The MULTII-PORT™ mounts on a standard DIN mounting rail and is offered in both AC and DC powered versions. This compact, low power module can enhance the functionality of a variety of serial communication devices.