1638   Clock Class 52 and 187

Created: 19 Nov 2018

Status: Drafting Implementation

Part: Part 9-3 (Precision Time Protocol Profile)

Links:

Page: 10

Clause: 7.4.3

Paragraph: 3

Category: Issue for edition 2 of this part

Issue

In 7.4.3, the definition of clock class 52 and 187 deviates from IEEE 1588 which specifies that a clock with class 52 may not be slave to another clock. Therefore, implementations adhering to 9-3 would differ from implementations adhering to 1588. Further, the indication of 1 us deviation is redundant since it is part of ClockAccuracy.

Proposal

Use exactly the wording to IEEE 1588 Table 5 and insert as "holdover specification" the value given in C.7.4.1

Discussion Created Status
Corrected in IEC 62439-3 Ed. 4 25 Jul 20 Drafting Implementation
1) Please adhere to the Tissue process; a new Tissue cannot start in status "final proposal" --> changed to red
2) Observe that 9-3 clause 7.4.3 NOTE 1 explicitly states that this is a modification to 1588 Table 5. Please describe in detail the impact of keeping the differences.
3) Currently, the transitions according to 7.4.3 are: from 6 to 7 (holdover) to 52 (time error between 250 ns and 1 us) to 187 (time error greater than 1 us). What would be the resulting transition steps of your prop0sal?
19 Nov 18 Discussion (red)
19 Nov 18 Ballot Period

 

Privacy | Contact | Disclaimer

Tissue DB v. 21.10.16.1