Tektronix, Inc. 39-740
P.O. Box 500
Beaverton, OR 97077

February 3, 1995

Mr. Clyde Camp
NESCOM Chair
c/o IEEE Standards Department
445 Hoes Lane
P.O. Box 1331
Piscataway, NJ 08855-1331

Re: P488.1 PAR Disapproval

Dear Mr. Camp,

I have received a letter from the NESCOM Secretary indicating that the Standards Board had disapproved the proposed I&M Society, TC-8 project to revise IEEE 488.1 to include higher performance protocols. As a NESCOM recommendation was being followed, I am writing to you to clarify the rationale behind this proposal and asking NESCOM to reconsider the PAR proposal based on this new information. If I actually need to resubmit a new PAR, please let me know.

The first disapproval reason was: "Based on a letter from WG3, International and US Standards have similar scope. Block 13 indicates no similar scope. Request sponsor supply reason why IEEE and international documents are different or re-submit under a new number as a new standard."

Perhaps I was in error in checking Block 13 as NO. I took this as referring to the high performance extension being proposed, not 488.1 itself. The IEC is not now working on a high-performance extension and I know of no other standards body working on such an extension. The IEC does have a standard, IEC 625-1, that tracks IEEE 488.1. They are virtually identical. As stated in the PAR Scope statement, an important concern of this extension is to maintain compatibility with the existing IEEE 488.1 standard and thus the existing IEC 625-1 standard. It is a primary concern that existing products and systems not be adversely impacted by this proposed extension.

Relating to the resubmission under a new number: This is not a good idea for several reasons. This proposal is very much a direct extension to IEEE 488.1. It is intimately related in technical detail with the 488.1 standard and forcing a new number will create confusion and produce an inferior standard as many references to IEEE 488.1 would have to be made. For clarity, several diagrams would have to be repeated with the additional state transitions shown. Keeping the extensions with 488.1 in the same document is the best way to assure that incompatibilities will not be created. 488.1 currently has several options for implementation, I expect this extension will just be an additional choice.

Let me offer you some background from my involvement with IEEE and IEC over the years. First, I have obtained a copy of the IEC letter from the SC65C/WG3 TAG Convener, Stephen Greer of Hewlett Packard that prompted your action. I can understand your concerns from his comments but I feel his statement that further modification of IEEE 488.1 will "forever destroy the equivalence" with IEC 625-1 is overstated. I have attended the last two WG3 TAG meetings in Europe and it is true that the group discussed and voted to not work on high performance protocols for IEC 625-1. However, I did not find the opposition vehement to the point that this might not occur at some future time.

To date, two companies, National Instruments and Capital Equipment Corporation, have seen fit to develop such 488 protocol extensions outside of the IEEE. They have both done so in response to market pressures. Additionally, I received letters from individuals from several different companies urging this effort go forward. These are attached. As TC-8 chair, I felt there was sufficient grounds to discuss this at the TC-8 meeting and put it to a vote as to whether to sponsor a PAR or not. Mr. Greer was at the TC-8 meeting when the decision was made. He presented his case and relayed the WG3 TAG concerns but he lost the vote -- so we went forward with the proposal.

I believe the history of the relationship between IEEE I&M Society TC-8 and IEC SC65C/WG3 TAG is a good one. We have always cooperated. European members were active in the development of both IEEE 488.1 (then IEEE 488) and of IEEE 488.2. IEEE has generally been the technical leader, but we have always received valuable input from our European colleagues. In the past, in all cases, the IEC has worked to normalize their standard to the IEEE standard. This cooperation has included a complete rewrite of IEC 625-2 to match IEEE 488.2 and also included the IEC's dropping an alternate connector type for IEC 625-1 to match IEEE 488.1 requirements. I don't believe this current effort is any different and we will arrive at a consensus solution, whatever that may be. This is just a request to begin a project, not a final ballot. A lot of work and discussion still remains to be done. The industry will be served better by letting this project progress as it will benefit overall from one standard protocol not many proprietary ones.

The other points seem less serious. "Strongly recommend that patent issues be resolved prior to submission to REVCOM" and "Change WG3 to WG3 TAG." Neither National Instruments nor Capital Equipment Corporation has taken a hard-line stance on their relevant patents. I have included a letter from Capital Equipment Corporation whose language clearly indicates they are positive on this project proceeding. I believe the resultant standard will meet IEEE's patent-related requirements. We will certainly change future references to WG3 as WG3 TAG as suggested.

Thank you for your consideration.

Sincerely,

Bob Cram, TC-8 Chair