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WIRELESS & CONNECTIVITY
Web controllers with increased performance and functionality by Markus Bartat und André Pribil, Beck IPC
The embedded controller family IPC@CHIP from Beck IPC will be enhanced in terms of hardware and software functionality with two new devices featuring increased performance and memory plus new interfaces.
Figure 1. The new IPC@CHIP controller SC123 I Beck IPC has added two new controllers to its IPC@CHIP product family. These two additional IPC@CHIP® controllers in the embedded web controller family considerably improve the options available to the customer for selecting the most suitable controller for the task at hand. The IPC@CHIP controllers from Beck IPC are embedded controllers with pre-installed real-time/multi-tasking operating system, file system and TCP/IP stack. All IPC@CHIPs are provided with a CPU, RAM, flash and Ethernet. The previously available SC11, SC12 and SC13 controllers each come with a 512 KB RAM and 512 KB flash memory, and are contained in a DIL32 housing. The new controllers of the SC1x3 series offer more performance, memory and functionality than their predecessors. They are nevertheless fully software compatible as they use the same @CHIP-RTOS operating system. They will be available from the end of 2005 as series products and the new SC123 and SC143 controllers will be equipped with up to 8 MB RAM and 8 MB flash memory. The increased memory is almost entirely available to the user and is not used by the operating system. This improvement thus removes one of the key limitations of the previous controllers for very large custom applications. The new BGA housing with 177 balls allows the simultaneous use of all interfaces for the first time, as the pin multiplexing used by
the DIL32 controllers is no longer necessary. Thanks to the power-saving 3.3 V design, the heat dissipation is kept below 2 W despite doubling of the clock frequency to up to 96 MHz and the larger memory. The increased memory and performance also made it possible to implement a host of new software and hardware features which are described below in greater detail. Compared to the previous SC1x controllers of the IPC@CHIP family, hardware functionality has been considerably extended. This includes, for example, the provision of two CAN 2.0B interfaces. CAN is a serial bus system, which was originally developed for automotive applications in the early 1980s. Today it is one of the most used communication standards for industrial network applications. A full-featured CANOpen protocol stack can be provided on request that is based on the CAN-API of @CHIP-RTOS. CANOpen is a CAN-based higher layer protocol and provides a standardized embedded network with highly flexible configuration capabilities. A USB 1.1 interface has also been added to the SC123/SC143 IPC@CHIPs. The USB standard has now become an indispensable feature in the PC world. However, the use of USB-based components is also playing an increasingly important part in industrial environments. At present, USB is supported by the @CHIP-RTOS API in device
mode, and the addition of host functionality is planned for one of the forthcoming software releases. Whilst the SPI and I5C interfaces on the SC1x controllers were only software implementations, they are now featured on the SC1x3 controllers as genuine hardware-based interfaces. The hardware implementation essentially provides the benefits of a higher bus-speed and the recently available slave functionality. These two bus systems allow a host of peripheral components such as MMC/SD cards, digital/analog I/O modules or various sensors to be connected easily to the IPC@CHIP. The number of Ethernet interfaces has been increased to two, thus further expanding the range of possible uses of the IPC@CHIP in TCP/IP-based networks. The ability to remotely monitor and control system data and parameters over the internet creates savings in operational costs by reducing the need to send technicians. At the same time, however, the unsecured sending of sensitive data over the internet involves certain risks. SSL is the so-called secure sockets layer protocol, which is used on every web browser and web server to encrypt/decrypt secure transactions. It is the de-facto standard for securing transactions over the internet. SSL was originally developed by Netscape. However, SSL has since then become standardised by the IETF (Internet Engineering Task Force) under the name TLS (transport layer security) as [RFC 2264]. SSL 15 November 2005
WIRELESS & CONNECTIVITY worldwide want to be connected to the internet with a unique address, the remaining IP addresses will be used up very soon. Port/network address translation (PAT or NAT) or the dynamic allocation of addresses for a specific time is one of the commonly used temporary solutions to this shortage of addresses. However, these measures cannot solve the problem in the long term. With its 128-bit address length, IPv6 offers here a permanent solution. IPv6 addresses are written in hexadecimal notation. The individual 16-bit blocks are separated by colons. The first 64 bits are normally used for network addressing, whilst the remaining 64 bits of the address are used for addressing the host.
Figure 2. The RTOS architecture of the SC1xx controllers complements the TCP/IP socket interface. This makes any TCP/IP application a candidate for SSL encryption. The @CHIP-RTOS of the new SC123/SC143 controllers introduces new SSL API calls that allow the user to establish their own secured TCP/IP connections. An effective way to interface with a remote embedded device over the internet is by using a web browser on a PC. This eliminates the need to develop proprietary PC software. Every modern PC has a web browser which has SSL security built-in. You’re using SSL if your URL begins with “https://” rather than “http://” and you’ll probably see a padlock icon on your browser’s status bar. The @CHIP-RTOS of the SC123/SC143 controllers introduces an SSL web server, which can serve standard HTML pages, CGI pages, or Java applets. SSL works by establishing a session between two communication peers using public-key cryptography to exchange a secret value, which is then used to generate session keys for all symmetric cryptographic algorithms used for the SSL user data transfer. The usage of both asymmetric and symmetric encryption methods gives SSL the high security of public-key encryption and the performance advantage of symmetric-key encryption. In the @CHIP-RTOS, these additional security requirements for communication were met by integrating SSL. Support for IPSec is also planned for future @CHIP-RTOS releases over the course of this development for increased communication security. IPSec is a security protocol that is mainly used for establishing VPN connections. Unlike SSL, IPSec 16 November 2005
does not run on the application layer but is implemented directly on the IP layer. The protocols and technologies that have been used on the internet up to now were developed in the seventies and eighties. The IPv4 protocol is the one currently used by the internet and also the mainly privately used intranets. The IPv6 protocol is the first significant update of the internet protocol suite. IPv6 is fully interoperable with the current IPv4 network infrastructure, and is to be gradually added to IPv4 and replace it over the next few years and decades. However, exact forecasts cannot be made at present as to how long IPv4 will exist and to what extent IPv6 will replace the IPv4 protocol. IPv6 is now also supported as a network protocol by standard PC operating systems such as Windows 2000/XP and Linux. It is already being used for the backbones of internet providers. The main reason for the development of IPv6 was the problem of insufficient addresses with IPv4. The 32-bit address space of the IPv4 protocol provides about. 4 billion IP addresses. Although only 60 percent of these have been used so far, a rapid allocation of addresses would soon exhaust the remaining space available. The first major users of the internet (Americans and some Europeans) were allocated enormous address spaces (so-called Class A networks) with 16.8 million addresses each. These have been kept by the organisations concerned, without ever being fully utilised. Later newcomers to the internet such as South America and Asia in particular had initially missed out. As more and more people, machines and devices
Another benefit of IPv6 over IPv4 is the improved and simplified packet header format. This enables the IP packets to be routed considerably faster in the network, as well as ensuring a generally more efficient processing of IP packets by hosts and routers. IPv6 also offers improvements compared to IPv4 in terms of network configuration and administration thanks to its autoconfiguration protocol. An IPv6 host can generate its own link-local address from its Layer 2 MAC address (e.g. its Ethernet address). With this address it is then able to contact routers present in the network. It can then assign valid IP addresses for the network based on the address range information sent by the routers. An additional address conflict detection mechanism prevents the duplication of addresses in the network. The TCP and UDP protocols on the IP layer are also supported in IPv6. The application software still uses the socket interface for accessing network services. The existing socket interface was extended for IPv6, mainly with regard to the longer addresses now required for IPv6. These extensions make it relatively easy to port existing IPv4 applications so that they are suitable for both IPv4 and IPv6. All TCP/IP applications using IP addresses (e.g. Telnet, FTP or HTTP) must now also support the 128-bit format for IPv6. The SC123/SC143 IPC@CHIP controllers support both IPv4 and IPv6 in a dual TCP/IP stack. In this way, these controllers are already equipped today for future applications. IPv6 communication is possible both via the IPC@CHIP Ethernet interface and via PPP. The dual-stack architecture enables the IPC@CHIP to run IPv4 and IPv6 communication at the same time. Software applications can transmit and receive your data via both IPv4 and IPv6. The server services such as Telnet, FTP and HTTP servers, that are integrated in the @CHIP-RTOS, are naturally also accessible via IPv6. The TCP/IP socket interface was extended accordingly for IPv6 and is available as part of the @CHIP-RTOS API. I
