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Reach for a Higher Standard

By Kevin Russelburg

The Telecommunications Industry Assn. (TIA) Subcommittee TR42.9 on Industrial Telecommunications Infrastructure is tasked with publishing TIA1005, the standard for Industrial Ethernet. Manufacturers of voice and data communication devices are well-represented in this subcommittee. Therefore, the focus tends to be mainly on the construction of the products, not the ease of installation. As it regards industrial network connection techniques, this is not good.

In response, committee members from the design and installation community are attempting to address the ease of installation issue by introducing proven industry practices for inclusion into the standard.

Standards Make It Easier, Right?

Industry standards are written to establish a set of rules for everyone to comply with. They are written for manufacturers to develop products that are intermatable and interoperable with other manufacturers' products, but, when written correctly, the end user usually is the primary beneficiary of standardization.

The standard should offer choices to end users that are best-suited for their application or environment. For example, RJ-45 is a very good interface for four-pair applications, but might be too large or overkill design-wise for certain applications. The option to use an M12-4D should be available when only two pair are required, or when panel space is an issue. A third option may be to include what is commonly known as a micronode, when floor space is critical, or when moves, adds or changes are common.

"Today, we have industrial IP67 RJ-45 connectors not because they are the perfect answer but because of the cabling industry's fixation with that style of connector. The industry needs a standard to deliver ease of installation, and provide the greatest benefit to the end user, not the manufacturers," argues Peter Sharp, senior electrical consultant with Giffels Associates (www.giffels.com) a Canadian engineering firm with extensive industrial and corporate IT infrastructure design experience.

A Standard Value

Much like our judicial system that requires the burden of proof rest with the prosecution, standards committees also must demonstrate that the directives they write add value. Especially in industries where sound practices already have been adopted. Essentially, there must be clear and convincing evidence for adopting a standards-based approach.

Standards organizations are attempting to specify a solution, or set of solutions that will stand up to harsh industrial environments. But, because those standards bodies are comprised mainly of manufacturers rather than installers or end users, the standard tends to focus on making connectors robust enough to handle the environment and not on making it easier or more efficient to install. Easy-to-install connectors can clearly benefit the end user by speeding installation and lowering the time and costs associated with implementation. "When an installer follows the standard for system integration, there is a higher level of comfort that the system will work," says Bob Lounsbury, principal engineer for Rockwell Automation and vice-chair TIA 42.9 Industrial Telecommunication Infrastructure; chair, ODVA EtherNet/IP Physical Layer; and chair, ControlNet Intl. Physical Layer. "Therefore, the standard must be written to protect end users by keeping their best interests in mind."

Once the decision has been made to standardize, the next task is to decide what to standardize on. For intermatability, the Open DeviceNet Vendors Assn. (ODVA) adopted both M12-4D for two-pair applications, and RJ-45 to satisfy the needs of four pair. "Due to the fact that the RJ-45 is so entrenched in the industry, it must be included in the standards, but for smaller solutions, an M12 is also needed", says Lounsbury.

In response to the standard, the RJ-45 interface currently has a few companies manufacturing industrial-rated solutions (Figure 1). Siemon Co., Molex and Surtec all offer intermatable "bayonet"-style designs. To be industrial-rated, the connectors must meet an IP67 rating (protection from dust and temporary water immersion). "As long as all RJ-45 or M12-style connectors have the same interface on the sealing capsule and are interoperable electrically, then end users can enjoy the benefits of standardization", says Brian Shuman, RCDD, secretary of the TR-42.9 Industrial Telecommunications Infrastructure Subcommittee; member of the EtherNet/IP PL JSIG, and senior. product development engineer, Belden Electronics.

Figure 1: Seal the Deal

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