Profibus, Profibus International, Foundation Fieldbus, and HART have formed a working group to develop a specification that will give common interface using a wireless gateway. "We want to give users some assurance that whatever they chose [Foundation Fieldbus, Profibus, or Profinet], they are going to be able to use it going forward," says Carl Henning, deputy director at PTO, Profibus, and Profinet North America. According to Henning, the group will look at both WirelessHART and the ISA standard, although because WirelessHART is complete, Profibus has been working mainly with that standard. "I've been told that we will probably see the Profibus gateway by the end of the year. This should help users because it will result in a common interface so they won't be stuck deciding which wireless sensor network to choose."

Says Karschnia, "It seems it would be worthwhile for SP 100 to change its focus from the bit-and-byte communication sensors to bigger problem of gateways." (In a network, a sensor transmits data, the data hops through a time-synchronized mesh protocol network, and arrives at a gateway.) "ISA should focus on how does that gateway will interface to the rest of the process control systems that exists—to the DCS, to the historians, to the business systems, and to the diagnostics systems. Once someone defines that, then the industry will adopt wireless more readily. To date, Emerson has its solution, Honeywell have its solution, and everyone will have a different solution. That is where ISA can add value."

Henning offers this perspective: "The thing to remember is that it doesn't matter who puts out the standard, it's what the users adopt that is going to be important. From that standpoint, I like the idea of having competing standards. The users are winners by having competitions because the standards organizations are spurred on to do better by that competition. There is a limit, but I think with two or three competing technologies, it's a positive."