4-Port RS-232/RS-422/RS-485 PC/104 Module

Our Emerald-MM PC/104 module gives you 4 serial ports operating at speeds up to 115kbps. The board is available in several models with different combinations of jumper-configurable serial protocols:
EMM-XT 2 ports RS-232, 2 ports RS-232/422/485
EMM-4485-XT 4 ports RS-422/485
EMM-4M-XT 4 ports RS-232/422/485

In RS-232 mode, the full complement of standard PC serial port signals (8 signals + ground) are provided for each port and are grouped onto two 20-pin headers (2 ports per header). In RS-422 mode, Signals RX+, RX-, TX+, and TX- are provided, along with ground. In RS-485 mode, signals TX+/RX+ and TX-/RX- are provided, along with ground.

A 16C554 quad serial port IC is used for the serial ports. This chip supports data transfer rates up to 115kbps and contains a 16-byte programmable FIFO buffer for each port to minimize processor overhead.

Flexible Configuration

Emerald-MM offers more interrupt level and I/O address options than other quad serial port modules. Therefore, integrating the board into your computer system is a simpler task. Eight different I/O address combinations and 10 different interrupt levels are available.

Full Interrupt Sharing

Any number of ports can share the same interrupt level. And if you have two boards in one system, both boards can share the same interrupt level as well. An interrupt status register is provided to indicate the status of each serial port’s interrupt request signal. This register is especially useful in Windows NT.

Designed for the Embedded World

Another distinguishing feature of Emerald-MM is its low-power +5V only operation. This board needs absolutely no +12V or -12V to operate. Extended temperature operation (-40 to +85°C) is also standard.