Industrial Ethernet Top 10

12-Jul-2010
Industrial Ethernet - The top 10 tips to help you make great product selection and design decisions.

1. Topology. While commercial networks tend to be 'star' shaped with central connection points, industrial networks use a variety of interconnections, and rely on fast-recovery redundant links (ring or coupling) for added reliability.
   
2. Power Supply. Industrial equipment relies on hard-wired high quality 24Vdc supplies - not plug packs held in place with cable ties or tape. Capacity for redundant power supply connection is preferred - especially if the supply is shared with other devices.
3. Mounting. Desk mount equipment is not suitable for industrial mounting. This before and after photo shows the space saved and reliability enhanced replacing a domestic product with an industrial one.
   
4. Environment. Tolerance to vibration, extremes of temperature and EMI are all part of the requirements for industrial products. Standard temperature rating range is typically 0ºC to 60ºC, however extended ratings of -40ºC to 70ºC and even 85ºC accommodate the most demanding applications. Few field cabinets have the luxury of air conditioning.
5. Network Availability. Industrial applications tend to be more time critical, where even a network downtime of a few seconds can disrupt production cycles. Mechanisms for real-time fault identification (Network Management Software, SNMP monitoring), and procedures for rapid replacement and configuration (using field-changeable physical memory) of failed components are essential to reduce production losses.
6. Network Convergence. While commercial networks tend to connect Servers, Workstations and Printers, industrial ethernet networks will often, in addition to these, have VFDs, IO, HMI terminals, and increasingly, voice and video. This range of different demands introduces special demands in network management. Hubs, unmanaged switches, and domestic grade managed switches just don't provide the functions needed to ensure these competing services play nicely together.
7. Network Segregation. Small networks are generally better than big ones, and you have only three choices when you want to make your big one behave like lots of small ones; Physical Separation (often not practical), Routing (more expensive and complicated) and VLANs. Often overlooked because of incorrect perceptions of complexity, this 'poor man's router' is a free way of segregating a network into manageable chunks. Well, free if you have an industrial grade managed switch!
8. Control Integration. Network performance visibility is now gaining prominence, and there are two main ways to do this. Network Management Software can provide not only OPC tags to deliver information, but can provide real-time status display objects to embed directly into SCADA. The switches themselves can also deliver, via protocols like Profinet or EtherNet/IP, status tags such as port loads or error counts directly to the PLC.
9. Real-Time Capability. Critical safety interlocks, Cyclical IO and Drive/Motion applications require real-time delivery of data, and network components must be equipped with the advanced functions to deliver this data reliably and timely. 
10. Standards. Apart from the common IEEE 802.11 standards, industrial applications have industry specific standards issued by a number of bodies. Common examples relate to transport, shipping and power stations.

The Hirschmann range of industrial ethernet equipment is designed to meet all these requirements, and hence support your mission critical networks.

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