EM203A Ethernet-to-Serial Module


The EM203A is an Ethernet module for onboard installation. Module hardware includes one 10/100BaseT Ethernet port (standard Ethernet magnetics are NOT integrated into the module), one CMOS-level serial port, and an internal processor, whose firmware acts as a bridge between the Ethernet and the serial port. The Ethernet "side" of the module connects to the RJ203A jack/magnetics module , a standard Ethernet magnetics circuit (such as YCL-PH163112) or RJ45 connector with integrated magnetics. Serial "side" interfaces directly to the serial port pins of most microcontrollers, microprocessors, UARTs, etc. The module additionally features four status LEDs onboard.

From the hardware standpoint, the EM203A can be viewed as a universal platform suitable for running a variety of applications. It is the application firmware, not the hardware that gives the EM203A most of its functionality. The EM203A is offered with two distinctively different kinds of application firmware:

"Serial-to-Ethernet" firmware, currently in its 3rd generation ("Release3"), turns the EM203A into a ready-to-work serial-to-Ethernet converter that can connect almost any kind of serial device to the Ethernet (TCP/IP) network. This firmware has fixed functionality; you adjust the way the EM203A behaves by specifying the values of programmable parameters (settings) defined in this firmware.
TiOS (Tibbo Operating System) firmware turns the EM203A into a BASIC-programmable controller. When running TiOS, the EM203A has no pre-defined functionality -- it is your BASIC application that defines what the EM203A will do. TiOS and BASIC programming are covered in a separate Manual ("TAIKO Manual").

The application firmware of the EM203A can be upgraded through the module's serial port or Ethernet port. Serial upgrades are facilitated by a so-called Monitor - a fixed "service" firmware inside the EM203A. Network upgrades rely on the application firmware, that is, the firmware can "upgrade itself".

The EM203A is supplied with "serial device server" firmware pre-loaded. If you wish to receive the module with TiOS firmware, please specify option "P" device on your order. Alternatively, you can just load the TiOS firmware by yourself. Current firmware versions are posted on our website.


The EM203A module features a heat-conductive sticker. Protective paper of the sticker MUST BE REMOVED prior to installing the module onto the host PCB. More on this in the Thermal Considerations topic.