Elettrolinux

uLan is multi-master message oriented communication protocol which utilizes RS-485 signal levels. Use of 9-bit character simplifies transfer of binary data. Characters are transferred same way as for RS-232 asynchronous transfer except parity bit, which is used to distinguish between data characters and protocol control information. A physical layer consists of one twisted pair of leads and RS-485 transceivers. Use of 9-bit character simplifies transfer of binary data and for intelligent controllers can lower the CPU load, because of the CPU need not to care about data characters send to other node. Producers of most microcontrollers for embedded applications know that and have implemented 9-bit extension in UARTs of most of today’s MCUs, e.g. some of them are all Intel 8051 and 8096 based MCUs with UART, members of Motorola 683xx family (like 68332, 68376 and so on) and Hitachi H8 microcontrollers. Package ul_drv is the Linux device driver designed to access the uLan network. Today supported hardware is ISA i82510 RS-485 card, support for PCI card equipped by OX16C950-PCI controller or simple active converter dongle for standard PC RS-232 ports. Source tree contains directory containing driver kernel source files, directory with userspace library hiding system dependent kernel driver access routines and some example utilities. Click here for uLan software and documentation pages.