In response to the need for a sealed, IP67-ratedRJ-45 solution,

many component manufacturers provide a standard intermatable

bayonet-style RJ-45 connector.

If too many companies manufacture a unique, proprietary solution industry intermatability suffers. "Commonality benefits everyone," adds Shuman. "The marketplace will be larger if everyone uses the same technology since proprietary solutions limit the total market. The end users would enjoy more choices among suppliers and benefit from the economies of scale."

Voices for Choices

The commercial office environment clearly is standardized on the RJ-45 interface. The RJ-45 is a long-established and familiar plug-and-jack combination. It also is a relatively inexpensive solution,in the office that is. However, the cost of encapsulating an RJ-45 plug and jack to meet the IP67 rating for industrial applications increases the price significantly. That fact, say many industrial users, presents the argument for choices to be included in the standard.

Many companies outsource the design and installation of their data systems to consulting companies well-versed in the industry. Therefore, the installers that are specifying systems are the customers, or end users. A number of sound industry practices have been adopted in the absence of a real standard. Designers and installers have developed and used these methods extensively to keep the integrity of the connection, while keeping in mind ease of installation.

One such practice is to put the connection inside a protected enclosure, such as the terminal strip method, or micronode. Accordingly, the definition of a micronode reads something like the description of a small telecommunications enclosure. The micronode method employs an enclosure to protect the cable terminations, active switch, and power supply. Mechanical seals at the entry point of the cable protect against ingress of liquids and dust. "Most companies we work with are making their terminations inside cabinets, or enclosures and try to avoid terminating on the outside as much as possible," says Dino Mannarino, business development and electrical consultant for Impact Technical Products, a telecommunications design and installation firm. "A micronode installation is fairly common throughout the industry. If the standard does not address this practice by including it, or a similar method, then a large portion of the industry will be excluded from using standard methods."

Micronodes work well when system changes are frequent. Systems need to be versatile enough to accommodate the users' need to add or rearrange equipment on the factory floor. "Many of today's manufacturing facilities are in a constant cycle of change," says Jim Westerman, industrial market manager, Siemon Co. "Moves, adds and changes that are constantly occurring do not allow for the use of patch panels in an industrial environment."

However, micronodes do not address connections that must be made outside of an enclosure, such as to a PLC or other control devices. "Overcoming this limitation might require that the connector receptacle be mounted on the outside of the enclosure, but IP67-rated connectors are more costly and more space consuming than necessary," reminds Sharp.

Various committees are currently preparing documents to address the need for standardization, and ISO/IEC, ODVA, TIA, CENELEC, and IOANA are all contributing. "With the number of standards bodies out there generating documents for industrial environments, following the same path is vitally important," says Lounsbury. "If all groups or consortiums go down a different path, our industry will be a mess and customers will ignore the standard."

The Matrix

To help the system designer or installer develop a solution that fits end user needs, selection tools will be available in the standard. These tools help avoid over or under-specifying a system.

Mechanical, Ingress, Climactic and Electromagnetic (MICE) is an environmental matrix used to help the installer or system designer specify the level of compliance they need (Figure 2). "The matrix defines the operating environment so that users can purchase the appropriate components," explains Robert Connell, RCDD structured cabling system specialist for Siemon Co.

Figure 2: Of MICE and Designers

The CENELEC Mechanical, Ingress, Climatic and Electromagnetic

(MICE) table used to specify required compliance levels is the model

for development of a similar table in the TIA standard.

Standards are living documents, so if another industry segment emerges and needs Ethernet, then additional solutions may also need to be included. "The ODVA DeviceNet standard addresses this requirement by using a structured guide to determine if additional solutions need to be included into the standard," adds Lounsbury. "In addition, DeviceNet allows for application-specific compliance. These are usually engineered systems and it's up to the customer to ensure compliance."

Two's Company, Three's Better

Products that comply with industry standards usually translates into lower cost. The exception comes when there is only one style or installation method. In this case, having a standard that only includes an RJ-45 interface does not seem to benefit the entire industry. "If a standard delivers only one solution, then the standards organization has not done its job," says Lounsbury. "Likewise, too many choices can have an adverse effect. Companies are asking for clear solutions, and not to leave [the issue] open. Proprietary solutions are not good for industry."

Regardless of the interface, performance must be the deciding factor. "There are good performance reasons to allow multiple connector types such as RJ-45 and M12-4 D," says Shuman. "The M12 connectors are smaller than their equally IP67-sealed RJ-45 cousins. When space is a constraint, the M12 connector provides higher performance and can be a good choice."

And, as previously stated, when frequent changes are the order of business, the micronode might be the best answer.

The installer community is concerned that not enough attention is being paid to existing practices, and how adopting those practices may speed-up the formalization of structured cabling in the industrial setting. "Standardization is a good servant, but a poor master, adds Sharp. "For serious progress to be made in the industrial Ethernet market, recognition is required of the shop-floor requirements of the industrial IT practitioner. Currently, there is too much dependence on the use of commercial building practices, with attempts made at forcing them into an industrial setting."

Ultimately, the customer will decide whether they want to be standards compliant, or not, but "keeping ease of installation in mind and creating a standard that offers choices will ultimately lead to a greater number of end users choosing to be standards compliant" adds Connell.

Kevin Russelburg , is a freelancer writer with significant network systems and electronics device experience. You can reach him at [email protected].