Ruggedized Ethernet Cabling(blogger@L-com.com)
L-com recently introduced a new line of ruggedized Ethernet cables so I thought I would post on some of the features of these cables and why they matter. Ethernet, as you know, has seeped in to nearly every facet of business and life. Now, connectivity is not only essential in homes and offices, but often in industrial sites, large-scale construction sites, harsh environments such as jungles and deserts, and in dangerous or active combat zones. In many cases, cellular connectivity is available, but not all. What happens when you have a location that requires a physical Ethernet structure, but the location itself is damaging or corrosive to that structure?
One aspect of ruggedized Ethernet cables is that they are IP68 rated. What does that mean? IP stands for Ingress Protection, and is a standardized method of determining how resistant to ingress, such as dust, dirt, sand, and moisture, a connection is. There is a great FAQ about IP ratings on L-com's website here. The IP68 rating is the highest rating attainable, meaning when properly mated the connection should be completely protected against dust and protected against long periods of immersion in water under pressure. Your application may not require quite that degree of protection, but it is usually best to err on the side of caution and get a cable that is more protected than you need.
Ethernet cables are typically composed of four twisted pairs of conductors. The twisting in the conductors allows the data to move quickly and be resistant to EMI/RFI. This kind of cabling is typically called UTP, which stands for Unshielded Twisted Pair cabling. Unshielded cable is usually preferred because it is lighter, cheaper, and the shield needs to be drained and is often unnecessary.
But there are circumstances when Shielded Twisted Pair (STP) is required. The shield, when properly drained at both ends, absorbs and re-directs much of the Electro-magnetic interference (EMI) and radio frequency interference (RFI). These random signals that interfere with the data signal can dramatically slow down a network as the nodes need to re-send the packets frequently. In extreme cases, such as near heavy-duty power lines or large magnetic devices, the signal will not be able to link at all. The shielding in the ruggedized cables protects against this interference much better than non-shielded cables.
Flame Retardant Thermoplastic Elastomer sounds like a mouthful, but FR-TPE jacketed cables are required in some applications. The durable and flexible compound that makes up the jacket is resistant to both UV and oils, which can break down the jacket over time and eventually destroy the cable. Also, the material will resist burning, which will greatly reduce the chance of a fire in one location "leaping" to another by burning along the cable jackets installed behind a wall or over a ceiling.
Often, the inside of a device is sensitive to the environment and the outer shell or chassis is meant to protect it. In these cases, no matter how well the chassis blocks out the elements of the outer environment, connector points in the chassis are a weak point. In these cases, transversely sealed jacks are required to ensure the two environments don't mix. L-com's transversely sealed ruggedized jacks are designed to prevent moisture from penetrating the connector while submerged under 1 meter for up to two days!
Another important consideration of the connectors on ruggedized Ethernet products is the conductivity. I mentioned earlier that the shield on the cable must be drained. This is done by electrically connecting it to ground. In some cases, the chassis itself is electrically connected to ground, so using a Zinc-Nickel (ZnNi) finished connector will allow the shield to drain directly into the chassis once it is mated. But, there are other cases where the chassis is not electrically grounded. In those cases, Anodized Aluminum (ANOD) finished connectors will prevent the EMI/RFI riding on the shield from draining and instead carry it through the jack into the chassis where it can be drained internally.
Quick note: L-com's eight new ruggedized Ethernet cable lines and ruggedized jacks are available off-the-shelf to serve your harsh environment Ethernet applications. We stock these products so you can rely on us to deliver the high quality that our brand represents. Check out all of our harsh environment Ethernet products and contact us if you need a custom product!