© Sealevel Systems, Inc.
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SeaLINK User Manual
Introduction to Shared COM Ports
Local COM ports on Windows-based PCs
Most serial devices in use are directly connected to the PC serial port via a cable.
This common "local device" configuration can be illustrated as follows:
This picture shows a serial device physically connected to the PC via a serial cable.
The Windows operating system provides Windows COM ports that applications use
for input, output, and control operations that "reach" through the serial cable to the
device.
Serial Servers
If a PC is running more than one or two applications that use a serial device, you can
quickly run out of places to attach them. Fortunately, you can employ an Ethernet
serial server that provides a pool of virtual COM ports for client computers on the
network to access. The serial server is situated between the desktop PCs and the
remote serial devices and appears to the network like this:
