Fred KozlofThe RJ45 connector is commonplace on computer systems in offices and homes, but there is often a need to network industrial equipment as well, resulting in a growing need for an Ethernet connector that can withstand harsh environments. In the past, designers would never consider putting an RJ45 receptacle on many industrial electronics boxes, because the existing connectors offered no sealing ability.

Since the RJ45 is the standard interface for Ethernet, the ideal connector would also be an RJ45, but one that can survive outdoors, in the rain, under the UV rays of the sun, in salty coastal air. Indoor applications could require exposure to liquid spray cleaning, machine coolant sprays and mists, dust and other contaminants.

Image 1. rec and plug metalIP67 is an Ingress Protection rating that defines the sealing ability for equipment used in industrial applications. While there could be an infinite number of conditions that effect operation--pressure, liquid, dust, time--the industry has chosen the simple test of an immersion in water, to a depth of 1 meter, for 30 minutes to be eligible for this rating. If there is no water seepage into the equipment, an IP67 rating is awarded.

Products that require IP67 ethernet connections can range from factory process equipment, to outdoor stadium scoreboards or traffic warning signs, to pole-top communications equipment, to portable electronics on the battlefield, or any equipment used outdoors by an emergency response team.

bayonet and M28 receptaclesTo meet these rugged environments, RJ45s can be made of several materials that are able to withstand such treatment: 
• An all-plastic body resists most chemicals it is likely to encounter, without threat of corrosion, while still providing a lightweight product if it needs to be portable. 
• Nickel-plated diecast versions also resist most chemicals but can tolerate more physically abusive environments as well as those requiring EMI shielding. 
• Metallized plastic versions offer a blend of each of the features of plastic and diecast versions mentioned above.

The connection type can also affect the reliability of an RJ45 connector in a harsh environment. There are two popular means for mating and securing a connection: the bayonet type and a threaded type.

Many customers like the 1/6th turn-and-click style of the Bayonet. It is fast and secure, even in high-vibration environments. It also lends itself to easy attachment or disconnect, even with gloved hands, for outdoor installations and servicing. Some customers feel that a more secure connection is provided by a threaded connection, however. In choosing between the two options, it really is a personal choice as both will work well.

trio of terminations RJThere is a solution for just about any application requiring a professional, reliable Ethernet port. Cable jackets are available in UV-stabilized types for outdoor exposure or standard types for indoor industrial environments.

All the above choices are for the outside port. The internal connections can be the convenient ‘coupler’ type, where a standard RJ45 can simply be plugged in or hard-wired options such as solder or IDC terminations, with or without strain relief, can be provided.

In short, designers now have the freedom to incorporate Ethernet ports into electronics used in outdoor and other harsh environments.