Diamond Systems EMERALD-MM-8E/EL : EMM-8E-XT Wide Temperature PCI/104-Express 8-Port Serial Module

Not every serial link needs isolation. When the devices sit in the same enclosure and share the host’s ground, a non-isolated port does the job with less circuitry. The EMM-8E-XT is the eight-port non-isolated build in the Diamond Systems EMERALD-MM-8E/EL series, a PCI/104-Express serial I/O module for rugged PCIe/104 stacks.

A PCIe x1 link on the PCIe/104 OneBank connector carries traffic to the host, and a 16550-compatible octal UART with 256-byte transmit and receive FIFOs serves all eight ports, so standard serial drivers in most embedded operating systems can use it. Automatic RS-485 transmit control handles direction switching in hardware. An on-board microcontroller keeps the configuration in flash and applies it at power-up, so there are no jumpers on the board.

Each of the eight ports on the EMM-8E-XT is set in software for RS-232, RS-422 or RS-485 with programmable 120 ohm termination, running at up to 1 Mbps in RS-232 mode and 10 Mbps in RS-422/485 mode through its own SP330 transceiver. Every port has ±15 kV ESD protection, short circuit protection and a latching connector. Eight auxiliary lines act as digital inputs or outputs, and seven can read 12-bit analogue inputs. The EMM-8EL-XT adds 2500 V RMS isolation on every port, and the EMM-4E-XT is the four-port non-isolated version.

Power comes from the 5 V DC bus at around 160 mA typical with outputs unloaded, and unused ports can be powered down. The EMM-8E-XT operates from -40 to 85 °C at 5 to 95% humidity, non-condensing, and Diamond Systems specifies it as MIL-STD-202G compatible for shock and vibration. Configuration runs from a graphical control panel, a console application or Windows and Linux drivers.