Diamond Systems DS-MPE-SER4OPT Opto-Isolated 4-Port PCIe MiniCard Serial Modules for Embedded Systems

Ground loops on long serial cable runs can damage a non-isolated board, and on a small host the only free expansion is often a PCIe MiniCard socket. The Diamond Systems DS-MPE-SER4OPT series puts four opto-isolated serial ports into that socket: serial MiniCards in the full-size PCIe MiniCard form factor, built for embedded and OEM systems where isolation is needed for safety or ground loop prevention.

Every DS-MPE-SER4OPT card uses a quad XR17V354 UART with a PCIe interface, 16C550 compatible with 256-byte transmit and receive FIFOs, and SP336 multi-mode transceivers. Data rates reach 1 Mbps in RS-232 mode and 10 Mbps in RS-485 mode. Each pair of ports is isolated by up to 500 V from system ground, using integrated isolated power and data components, careful layout and an insulation film on the underside that prevents accidental contact with components on the host board. Signals leave on two miniature latching connectors, two ports per connector, and RS-485 termination is jumper selectable.

Protocols are set in pairs, so the series comes preconfigured in three builds. The DS-MPE-OPT4232 has four RS-232 ports for point-to-point links to serial equipment. The DS-MPE-OPT4485 has four RS-485 ports for multidrop networks and longer cable runs. The DS-MPE-OPT4M22 splits the card into two RS-232 and two RS-485 ports for systems that need both on one card. Each ships with the CK-SER4M cable kit and a hardware kit with jumpers and screws, so the card can be wired to panel connectors straight away.

All DS-MPE-SER4OPT cards run from 3.3 V DC at 0.462 W and operate from -40 to 85 °C at 5 to 95% humidity, non-condensing. For high-vibration installations Diamond Systems can custom-configure the cards with 0 ohm resistors in place of the jumper blocks. Drivers cover Windows 7, XP, Vista and 2000 and Linux 2.6 kernels, and every card is RoHS compliant. Where vibration is a concern, the latching connectors help keep cables seated. Diamond SBCs with a PCIe MiniCard socket, such as the SATURN and ARIES, take the series without using a position in the PC/104 or PCIe/104 stack, which keeps those connectors free for other I/O modules.