Geneva, Switzerland—Dick Caro officially tendered his resignation Feb. 1 as convenor of the IEC SC65C/WG6 fieldbus committee. With the recent passage of the IEC ballot on the final draft of the IEC 61158 fieldbus standard, he fulfilled his agreement to finish work on WG6. Mr. Caro had led the subcommittee since 1993.

The fact that the standard now has seven additional parts, which parallel with the original committee products, makes it "ethically impossible" to continue as convenor, according to Mr. Caro. "This is not the standard for which the committee worked 13 years to complete," he says.

"Many of us on the committee feel that end-users have been cheated and denied the single standard for which we have worked since the beginning," adds Mr. Caro. "I feel that harmonization of the eight types of IEC 61158 will not be possible, nor will it be a worthwhile effort. The time has come to put the last 13 years behind us and move on to the future, which will be through Ethernet, Internet protocols, standardized automation objects, and wireless solutions.

"Only one of the eight parts looks to the future, and that is already fully specified and completed as Type 5, Foundation fieldbus' high-speed Ethernet (HSE) of the multi-part IEC fieldbus standard. From now on we should all concentrate on the creation of interoperable automation objects, not on the low-level network protocols."

When asked where users will go from here, Mr. Caro responded that they will go with whatever protocol their vendor uses. The recent IEC ballot names eight protocols, failing to produce one protocol as the standard. Frustration over this ultimately led to Mr. Caro's resignation from the IEC subcommittee. He noted that he is not resigning as chair of the ISA SP50 committee, nor as vp of technology for the ARC Advisory Group (Dedham, Mass.).