Industrial communications have changed greatly over the last several years, largely due to how quickly industrial Ethernet has been accepted and applied by manufacturers of all types. When industrial companies first began using Ethernet, the prevailing thought was to use single-purpose proprietary networks for real-time interlocking between machines and control systems and use Ethernet for transferring configuration and programming files, pushing data to and from human machine interfaces, or nightly summaries of production.
Technology advances and the advent of Industrial Ethernet has changed that. Standard, non-proprietary Ethernet is now used for real-time communication, control interlocking, and connection of literally all automation devices that aren’t connected directly to an I/O block.
As Ethernet’s use expanded, users added knowledge of star topologies and the need for hubs and switches to their existing knowledge of linear fieldbus topologies. In the process, they learned that the task of adding new devices to a network became easier. Merely plugging a cable into an available port and stringing it to some new device gave you virtually instant communications.
And unlike fieldbusses with smaller bandwidth, which theoretically limited the number of devices that could be connected to a network, industrial Ethernet provides:
- significant performance advantages;
- the ability to just run cable from point to point, providing a tremendous capability to add devices; and
- easy expandability with little or no planning required.
Ad Hoc Networks & Cabling Issues
This leap in flexibility, bandwidth, and performance that Ethernet brought to industrial networks created the concept known as an “ad-hoc” network. This style of a relatively flat and daisy chained network is terrific as long as everything is working.
The challenge comes when devices fail, cables start to deteriorate, or when someone adds a device that allows an external third party unauthorized access and data starts getting manipulated or mangled. Because an ad hoc network by definition and construction has little or no supporting documentation, once the network becomes unmanageable, production slows or services stop.
Suddenly what was an easy network to live with becomes a nightmare and emergency help is required to restore operations.
This reality, which is now being faced by numerous manufacturers, translates into the need for a true infrastructure for industrial Ethernet. A proper infrastructure allows for predictable performance and successful maintenance while allowing managed incremental modifications to the network. (For more information on ad hoc networks and converting them to viable Ethernet infrastructures, see the “Here’s Your Sign” article.
Beyond infrastructure issues, a review of common network maintenance issues reveals that the most challenging failures in any industrial network typically involve the physical cable. Ethernet devices are generally easy to find and service and connectors are often easily accessible and can be replaced with minimal difficulty. The cable connecting one device to another, however, is often inaccessible because it’s buried in a cable tray, wrapped around a moving machine, or is suspended forty feet in the air.
Despite the common issues associated with ad hoc network structures or cabling issues, Ethernet continues to be implemented at an unprecedented rate. And while Ethernet’s popularity is clear, users’ demands are becoming equally clear. Users want Ethernet networks to:
- Provide control and information from where it originates to wherever it needs to go—as fast, as deterministic, and as secure as needed for the application;
- Provide room to upgrade and expand in the same ad-hoc fashion as today, but with confidence that the additions won’t push the network over the edge;
- Offer a support system and expert help when needed, with pre-existing knowledge of the network so all forms of help are quick and easy;
- Make the network easy to manage so that users can do the work themselves when they want.
A Solution: The Belden Certified Industrial Network
To address these types of networking issues, Belden is offering the Belden Certified Industrial Network. This network is designed, installed, started up, tested, and documented by a qualified authorized provider. In addition, every network design and its installation test results are reviewed Belden’s engineers, with at least two sets of experts reviewing every application.
Proper Layer 1 devices (cables and connectors) are specified up front to allow for movement or other environmental factors, and proper Layer 2 devices (Ethernet switches and routers, wireless access points, security appliances) are designed in from the start to achieve the proper partitioning and functioning of the network.
Qualified installers route cables from end devices to switches, building a supportable infrastructure. Once installation is complete, physical testing ensures the network functions properly. All test results are reviewed by the installer, Belden and the customer. These results then become part of the permanent file of documentation.
The use of Belden tools and best practices ensures that the network functions as intended and is maintainable and expandable as needs change. Minor changes can often be made without the involvement of an integrator or Belden, which means problems can easily be remedied as they occur.
Belden and a qualified system integrator are able to provide an extended warranty and an ongoing relationship with the customer to help as the network changes and expands over time. This all adds up to significantly increased peace of mind, allowing the customer to focus on what they do best.