Power Over Ethernet Interoperability Guide

I_CUT Monitoring as Per AT Standard

In Fig. 6.8, we have also shown a narrow sliver called “I_CUT monitoring band.” As per Table 33-11 on page 45, this monitoring is optional. As per line 7 of the table, I_CUT can range from P_CLASS/V_{PORT_PSE} to I_LIM. But I_LIM is itself a range, so that does not sound quite right. Line 7 also has a typo, because the divide-by sign is missing in P_CLASS/V_{PORT_PSE}. In 33.2.7.7 on page 48, it is clarified that “The I_CUT threshold may equal the I_PEAK value determined by Equation 33-4.” We take it to mean that while doing this optional I_CUT monitoring, we can position this narrow sliver above the I_CONT threshold as shown in the figure, and below the I_PEAK threshold.