The Technobox 8503 provides sixteen industry standard 16550-based UARTs using RS485 signaling levels. Each port has 121 ohms parallel termination. The board's feature set is configured without using any jumpers, plug-on mezzanines, or complex FPGAs. Instead, functions are implemented by selective population of the boards eight configuration sections. At the heart of the design are two Exar XR17V358 Octal UARTs and sixteen Intersil ISL 3178E Half duplex RS485/RS422 transceivers.
The front panel I/O interface is a standard 68-pin SCSI-style connector. Neither PN4 nor P16 rear I/O is supported. Rear I/O capable variants (either air or conduction-cooled) can be built, however.
Various breakout panels and cable accessories are available to convert the 68-pin front panel I/O to suit user requirements. For example, Technobox P/N 4988 can be used to convert the output to eight DB9 connectors. The XMC interface connector is VITA 42 style. Technobox P/N 8506 is similar in function to Technobox P/Ns 2876 and 5463, offering an immediate solution for migrating from the PMC to XMC form factor.