Attachment to Letter Ballot IEEE I&M TC-8 on Approval of Project 488.1/D1.2
Comments on Negative Vote
The reasons for my negative vote on this project fall into two issue categories, technical and procedural.
Technical Issues
| Compatibility | The high speed data transfer scheme uses IEEE 488.1 signals in a way which existing equipment will not recognise, and which may therefore cause them to behave unpredictably. Perhaps of even more concern I the fact that this revision will lead to the destruction of the harmony between IEEE 488.1 and the IEC 60625-1 equivalent, which has benefited the standard with true international status up until the present time. |
| Complexity | The interlinked state machines of the existing IEEE 488.1 standard have been largely unchanged for over two decades, a fact which I believe has contributed to the success and wide acceptance of the standard. Introducing the additional complexity embodied in this revision is likely to lead to errors in interpretation. |
| Reliability | The high speed data transfer scheme relies on knowledge of cable lengths, which systems in general have no automated way of checking. If a cable length is changed without updating the data available to the system then unreliable data transfers could result, and furthermore could remain undetected. |
| User Benefit | The high speed data transfer scheme only provides a benefit in applications and devices where large blocks of data are transferred. It does not affect addressing cycles or other ATN true interactions, and is therefore of limited benefit. Also, it is clear that many applications requiring higher data transfer rates actually require rates significantly higher than the improvements offered by this revision, and would probably look to different interface technology altogether to meet their needs. |
Procedural Issues
| Conflict of Interest | I am concerned that the chairman of the working group for this project appears to have a conflict of interest in that the only currently available implementation of the high speed data transfer scheme is, as far as I am aware, a product of his employers. |
| Alternatives | I believe that this project should have been raised to the international level, particularly as an alternative proposal, which does not appear to exhibit the same technical flaws, is currently under the scrutiny of the IEC. |
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S. W. Lomas 26th July 1999