Roalan is introducing the OnRISC Alena embedded industrial computer. This ARM 9 RISC model is the latest member of the OnRISC family and, like the initial Alekto, it is based on an ARM9 RISC CPU and runs the full-featured Debian GNU/Linux operating system, based on Kernel 2.6. Alena is suitable for control and networking applications for industrial control, transportation systems, environmental monitoring and small office servers.
Alena features a fanless design, RISC-based architecture and operates reliably in an IP30 aluminium case in temperatures from -10 to 65degC. It is suitable for use in harsh environments, as typically encountered in industrial and factory automation applications. To enhance further such usage, an internal microSD reader is available as mass storage for operating system and user data. It connects to various fieldbuses via its rich interface options, including CAN support for CANopen
Many interfaces, like LAN, USB, I ²C, RS232/422/485 serial, digital I/O and MiniPCI-Slot, make it easy to connect various industrial devices to the OnRISC systems.
The Alena adds CAN to the supported interfaces, and offers two additional serial ports compared to the Alekto. Two digital I/O signals are isolated inputs, while two others are relay outputs. The other four signals behave bidirectionally as in the Alekto.
OnRISC systems run full-featured Debian GNU/Linux on the ARM operating system, including all device drivers for peripherals.
Linux Kernel 2.6 boots from a CompacctFlash card or the internal microSD reader. This Kernel has better support for USB devices, handles the Watchdog Timer of Alena and Alekto, and provides the udev file system for devices. Many other new features are detailed in the public Linux documentation.
One application field for OnRISC embedded computers is intelligent networking of production tools, such as CNC machine tools, PLC controllers and I/O controllers. These devices can usually be accessed only via RS232/422/485 or over Digital I/O, though fieldbuses may be connected to RS485 or CAN.
Roalan explains that the OnRISC Alena directly interfaces these devices via serial ports or digital I/O; at the same time, via Ethernet, it acts as a gateway to higher computer systems such as monitoring and/or control workstations. OnRISC systems can therefore supply the manufacturing devices with production data on demand, download their programs, buffer data from/to those devices, run maintenance tests or perform data protocol conversions.
The internal SD card can be used to separate the operating system and application or configuration files from production data such as protocol files or NC programs on the Compact Flash card. This means that the system is protected against accidentally removal. In addition, administrators can use the Compact Flash slot to upload new data and configurations, without the need for a network connection.
However, the OnRISC Alena can be readily connected to CAN networks. For developing applications, the VSCAN API is provided. This API also supports CANFestival, an Open Source CANopen Framework. CANopen unburdens the developer from dealing with CAN-specific details such as bit-timing and implementation-specific functions. It provides standardised communication objects for real-time data, configuration data and network management data.
An application designed to operate with USB-CAN on Alekto operates directly on Alena's CAN port, without any changes required.
Other Linux applications might use the LinCAN API, which is also available on Alena. This API also supports CANFestival and CANopen.
Follow the link for more information about the Alena embedded industrial computer.