Diamond Systems EMERALD-MM-8E/EL : EMM-4EL-XT Ruggedised PCI/104-Express 4-Port Serial Module with Opto-isolation

Many vehicle and transport systems need only a few serial links to sensors and other subsystems, but each of those links may cross between grounds at different potentials. The EMM-4EL-XT is the four-port isolated build in the Diamond Systems EMERALD-MM-8E/EL series, a PCI/104-Express serial I/O module that gives each port its own 2500 V RMS isolation circuit.

The host link is PCIe x1 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, each through its own SP330 transceiver, so most embedded operating systems can use standard serial drivers. Configuration lives in the flash of an on-board microcontroller and loads at power-up, so there are no jumpers.

Each of the four ports on the EMM-4EL-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. Every port has ±15 kV ESD protection and a separate latching connector. Eight auxiliary lines provide digital inputs or outputs, and seven of them can read 12-bit analogue inputs. The EMM-8EL-XT doubles the isolated port count to eight, and the EMM-4E-XT offers four ports without isolation.

The module runs from 5 V DC at around 160 mA typical with outputs unloaded. Staggered turn-on of the isolated power circuits limits inrush current, and unused ports can be powered down to save power. The EMM-4EL-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 Windows and Linux drivers are included.