IEEE 8023cn-2020 pdf free.IEEE Standard for Ethernet Amendment 6: Maintenance #13: Power over Ethernet over 2 pairs.
Change 1.4.323“Medium Dependent Interface (MDI)”(re-numbered from 1.4.324 due to the deletion of 1.4.294 by IEEE Std 802. 3b1-2018) as follows:
1.4.323 Medium Dependent Interface (MDI): The mechanical and electrical or optical interface between the transmission medium and the MAU (e.g., 10BASE-T) or the PHY (e.g., 1000BASE-T) and also between the transmission medium and any associated (optional per IEEE Std 802.3, Clause 33。Clause 104. and Clause 145) Powered Device (PD) or Endpoint Power Sourcing Equipment (PSE). aPSEOverLoadCounter
Generalized nonresettable counter. This counter has a maximum increment rate of 2 counts per second.
This counter is incremented when the PSE state diagram (Figure 33- 9 and Figure 145- -13) enters the state ERROR_ DELAY due to the ovld detected variable being TRUE. For Type 1 or Type 2 PSEs, if a Clause 22 MII or Clause 35 GMII is present, then this will map to the Overload bit specified in;
Change 33.1.4 as follows:
A power system, consisting of a single PSE, link segment section, and a single PD, defined as either Type 1 or Type 2, has certain basic parameters defined according to Table 33-1. These parameters define not only certain performance characteristics of the system, but are also used in calculating the various electrical characteristics of PSEs and PDs as described in 33.2 and 33.3.
It should be noted that the cable references use“DC loop resistance,” which refers to a single conductor. This clause uses“DC pair loop resistance,” which refers to a pair of conductors in parallel. Therefore, Rch is related to, but not equivalent to, the“DC loop resistance” called out in the cable references.
A PSE shall implement Altemative A, AlternativeB, or both. While a PSE may be capable of both Alternative A and Altermnative B, PSEs shall not operate both Altermnative A and Alternative B on the same link segment section simultaneously.
The PSE probes the link section in order to detect a valid PD detection signature. The PSE PI is connected to a PD through a link segment section. In the following subclauses, the link is not called out to preserve clarity.IEEE 8023cn pdf download.