Diamond Systems EMERALD-MM-8E/EL : EMM-4E-XT Optically Isolated 4-Port PCI/104-Express Serial Module

A small rugged stack often needs only a few serial links to devices housed in the same enclosure. The EMM-4E-XT is the four-port non-isolated build in the Diamond Systems EMERALD-MM-8E/EL series, a PCI/104-Express serial I/O module that adds RS-232, RS-422 or RS-485 ports to a PCIe/104 host without the isolation circuits of the EL models.

Traffic reaches the host over a PCIe x1 link on the PCIe/104 OneBank connector. A 16550-compatible octal UART with 256-byte transmit and receive FIFOs and automatic RS-485 transmit control serves the ports, so standard serial drivers in most embedded operating systems apply. An on-board microcontroller stores the configuration in flash and restores it at power-up, which removes configuration jumpers from the board.

Each of the four ports on the EMM-4E-XT is set in software for RS-232, RS-422 or RS-485 with programmable 120 ohm termination, at up to 1 Mbps in RS-232 mode and 10 Mbps in RS-422/485 mode. Each port has an SP330 transceiver, ±15 kV ESD protection, short circuit protection and its own latching connector. Eight auxiliary lines work as digital inputs or outputs, seven of them also as 12-bit analog inputs. The EMM-4EL-XT adds 2500 V RMS isolation to the same four ports, and the EMM-8E-XT doubles the port count.

Power is 5 V DC at around 160 mA typical with outputs unloaded, and unused ports can be powered down. The EMM-4E-XT operates from -40 to 85 °C at 5 to 95% humidity, non-condensing, and Diamond Systems specifies MIL-STD-202G compatible shock and vibration. A graphical control panel, a console application and drivers for Windows and Linux cover configuration and control.