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Home>AUTOMATION>Networks>Chips, Bricks & Modules

Chips, Bricks & Modules

15 March 2013

The market for industrial networking is now over 20 years old, and has changed beyond recognition. However, far from the expected rationalisation, there are more networks and protocols than ever, says David Folley, general manager, UK and Eire, HMS Industrial Networks

It is estimated that there are over 20 main open networks and 50 proprietary ones. When end users specify their preferred control automation network, it presents a real dilemma for device and equipment makers – who must be able to supply their machines or devices with the ability to communicate with any network or between different networks.

Conventional wisdom is to use a modular communication gateway, and with millions of such devices already in use, this popular approach is readily available for almost all open and proprietary networks.

There will, however, be times when a modular solution is inappropriate, due to its physical size or cost. For this reason, gateway manufacturers have also started releasing their core technologies in the form of chips and dedicated boards, known as bricks. These are ideal for high volume and PCB level integration.

In manufacturing, high performance industrial automation networks are increasingly expected to provide faster control, reduced cycle times, and to support higher levels of secure data transfer. Automation systems must accommodate traceability, increased use of robots, and cope with increases in monitoring due to legislation and safety requirements.

Whilst the hardware manufacturers promote their proprietary systems for speed and reliability, open networks have gained in popularity because no single producer provides connected devices for every application, and end-users seek plug-and-play style automation for all networked devices. The benefits to users of open networks include:
  • Selectivity of best in class products from a range certified compatible products
  • Cost reductions by a multi-vendor platform
  • Long assured lifetime oftechnology and support
  • The opportunity of joining a user group and participating in new developments
Gateway communication devices are particularly attractive to third party manufacturers seeking to integrate networking into their devices. Previously there were a number of considerations to take into account before developing network-compatible versions of
their products, such as:
  • Which of the 70 or so networks are most important to your business?
  • Do you have the in-house expertise to develop a range of network interfaces?
  • Do you have the development capacity or budget to develop a range of network interfaces?
  • Are projected volumes high enough to meet target ROI?
  • Can we manage the maintenance, certification and future support?
Because of this, equipment makers have increasingly turned to established specialist companies that develop, produce and market intelligent communication technology for automation equipment and can connect devices to any major network protocol or enable interconnection between different industrial networks.

They work closely with both manufacturers and the open network associations to ensure their gateway products are fully compatible, and routinely conduct conformance tests of all such devices. This offers access to the latest technology without significant investment or risk.

There are many considerations in selecting a suitable gateway device. In higher volume applications an embedded device may be most appropriate, whereas connecting a smaller number of disparate devices may require a different approach.

A typical embedded interface module utilises a plug-in design in which the different network interfaces can be plugged into the product’s control board by way of a standard CompactFlash connector. Different plug-in modules provide device makers with interfaces allowing connectivity to the leading industrial networks.

As the modules’ software interfaces are independent of network protocol, automation devices with a suitable slot can use any compatible plug-in module. This allows the host application to support all major networking systems using the same software driver, without loss of functionality or performance. For example, it is easy to replace the Profibus module with an EtherNet/IP module and be instantly connected to that network without the need for hardware and software changes in the automation device.
A custom developed network communication processor delivers a small, flexible, affordable high performance interface with low power consumption. The performance and flexibility offer a fast time-to-market of between one and three months. Typical applications include HMIs, robot controllers, drives, micro PLCs, valve manifolds, instrumentation, weigh scales, temperature controllers, bar-code scanners, I/O blocks and welding controllers.
Modules are categorised into two types:
  • Active modules that support the fieldbus and Ethernet networks – the application interface can be accessed either by the dual-port RAM or fast serial line.
  • Passive modules provide the physical layer network interface and transparent pass-through for serial data between the network and host. These are available for RS-232, 485, USB and Bluetooth.
Both are installed in the host device using the standard CompactFlash connector.

The recipient device uses a single chip, high performance network processor. This ASIC has a high performance, low power RISC processor including Profibus, Ethernet, CAN and other communication interfaces as well as internal RAM and Flash memories.

The device is for mounting in the PCB and requires the customer to supply a few add-on components for integration with the host processor.

The brick type interface is for device manufacturers who are looking for a semi-integrated solution where connector flexibility, size, cost and time-to- market are key elements, and gives users the flexibility to add their own connectors on the network side. (DSUB, RJ45, M12 etc)

It incorporates the network processor and components required for a fast, cost effective fieldbus or Ethernet connection for the industrial device. The brick includes network functionality and is ready to communicate, which results in a reduction of development efforts and a fast time-to-market.

High performance versions are also available for high-end industrial Ethernet and fieldbus applications requiring fast network cycles. They use a flash-based, single chip network processor that includes a high-performance ARM core and an FPGA (field programmable gate array) fabric.

The FPGA fabric is used to implement the various real-time Ethernet interfaces, while the ARM core is used to run the protocol and application stacks.

One such example is a new network processor from HMS Industrial Networks targeted at real-time industrial Ethernet applications. The Anybus NP40 allows industrial devices to communicate over any industrial network and forms the core of HMS’s new CompactCom chip, brick and module concept.

The NP40 can support several different Industrial Ethernet and Fieldbus networks. Device manufacturers simply install a communications interface into a product and then download the firmware they need before shipping their products.

The NP40 exhibits virtually zero delay (in reality a few microseconds) in passing signals between the network and host API (Application Programming Interface). This makes it highly suitable for applications that require high level synchronisation or motion profiles.

"Industrial Ethernet is now demanding more performance and a new architecture,” says Jörgen Palmhager, chief operating officer at HMS. "The new industrial Ethernet networks are getting more and more specialised, which demands a lot from a network processor that is to handle the ‘translation’ between different networks and protocols.”

A real-time-switch is integrated into the FPGA fabric and it supports synchronous cyclic messaging in real-time networks such as PROFINET IRT, Powerlink, EtherCAT and Sercos III. Since the network processor is flash-based, it can be re- programmed for several different industrial Ethernet networks. 

Key Points

  • Gateway manufacturers have started releasing core technologies in the form of chips and dedicated boards, known as bricks
  • Open networks have gained in popularity because no single producer provides connected devices for every application
  • Gateway communication devices are attractive to third party manufacturers seeking to integrate networking into their devices